--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/share/classes/java/lang/String.java Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,3118 @@
+/*
+ * Copyright (c) 1994, 2017, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package java.lang;
+
+import java.io.ObjectStreamField;
+import java.io.UnsupportedEncodingException;
+import java.lang.annotation.Native;
+import java.nio.charset.Charset;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Comparator;
+import java.util.Formatter;
+import java.util.Locale;
+import java.util.Objects;
+import java.util.Spliterator;
+import java.util.StringJoiner;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import java.util.regex.PatternSyntaxException;
+import java.util.stream.IntStream;
+import java.util.stream.StreamSupport;
+import jdk.internal.HotSpotIntrinsicCandidate;
+import jdk.internal.vm.annotation.Stable;
+
+/**
+ * The {@code String} class represents character strings. All
+ * string literals in Java programs, such as {@code "abc"}, are
+ * implemented as instances of this class.
+ * <p>
+ * Strings are constant; their values cannot be changed after they
+ * are created. String buffers support mutable strings.
+ * Because String objects are immutable they can be shared. For example:
+ * <blockquote><pre>
+ * String str = "abc";
+ * </pre></blockquote><p>
+ * is equivalent to:
+ * <blockquote><pre>
+ * char data[] = {'a', 'b', 'c'};
+ * String str = new String(data);
+ * </pre></blockquote><p>
+ * Here are some more examples of how strings can be used:
+ * <blockquote><pre>
+ * System.out.println("abc");
+ * String cde = "cde";
+ * System.out.println("abc" + cde);
+ * String c = "abc".substring(2,3);
+ * String d = cde.substring(1, 2);
+ * </pre></blockquote>
+ * <p>
+ * The class {@code String} includes methods for examining
+ * individual characters of the sequence, for comparing strings, for
+ * searching strings, for extracting substrings, and for creating a
+ * copy of a string with all characters translated to uppercase or to
+ * lowercase. Case mapping is based on the Unicode Standard version
+ * specified by the {@link java.lang.Character Character} class.
+ * <p>
+ * The Java language provides special support for the string
+ * concatenation operator ( + ), and for conversion of
+ * other objects to strings. For additional information on string
+ * concatenation and conversion, see <i>The Java™ Language Specification</i>.
+ *
+ * <p> Unless otherwise noted, passing a {@code null} argument to a constructor
+ * or method in this class will cause a {@link NullPointerException} to be
+ * thrown.
+ *
+ * <p>A {@code String} represents a string in the UTF-16 format
+ * in which <em>supplementary characters</em> are represented by <em>surrogate
+ * pairs</em> (see the section <a href="Character.html#unicode">Unicode
+ * Character Representations</a> in the {@code Character} class for
+ * more information).
+ * Index values refer to {@code char} code units, so a supplementary
+ * character uses two positions in a {@code String}.
+ * <p>The {@code String} class provides methods for dealing with
+ * Unicode code points (i.e., characters), in addition to those for
+ * dealing with Unicode code units (i.e., {@code char} values).
+ *
+ * <p>Unless otherwise noted, methods for comparing Strings do not take locale
+ * into account. The {@link java.text.Collator} class provides methods for
+ * finer-grain, locale-sensitive String comparison.
+ *
+ * @implNote The implementation of the string concatenation operator is left to
+ * the discretion of a Java compiler, as long as the compiler ultimately conforms
+ * to <i>The Java™ Language Specification</i>. For example, the {@code javac} compiler
+ * may implement the operator with {@code StringBuffer}, {@code StringBuilder},
+ * or {@code java.lang.invoke.StringConcatFactory} depending on the JDK version. The
+ * implementation of string conversion is typically through the method {@code toString},
+ * defined by {@code Object} and inherited by all classes in Java.
+ *
+ * @author Lee Boynton
+ * @author Arthur van Hoff
+ * @author Martin Buchholz
+ * @author Ulf Zibis
+ * @see java.lang.Object#toString()
+ * @see java.lang.StringBuffer
+ * @see java.lang.StringBuilder
+ * @see java.nio.charset.Charset
+ * @since 1.0
+ * @jls 15.18.1 String Concatenation Operator +
+ */
+
+public final class String
+ implements java.io.Serializable, Comparable<String>, CharSequence {
+
+ /**
+ * The value is used for character storage.
+ *
+ * @implNote This field is trusted by the VM, and is a subject to
+ * constant folding if String instance is constant. Overwriting this
+ * field after construction will cause problems.
+ *
+ * Additionally, it is marked with {@link Stable} to trust the contents
+ * of the array. No other facility in JDK provides this functionality (yet).
+ * {@link Stable} is safe here, because value is never null.
+ */
+ @Stable
+ private final byte[] value;
+
+ /**
+ * The identifier of the encoding used to encode the bytes in
+ * {@code value}. The supported values in this implementation are
+ *
+ * LATIN1
+ * UTF16
+ *
+ * @implNote This field is trusted by the VM, and is a subject to
+ * constant folding if String instance is constant. Overwriting this
+ * field after construction will cause problems.
+ */
+ private final byte coder;
+
+ /** Cache the hash code for the string */
+ private int hash; // Default to 0
+
+ /** use serialVersionUID from JDK 1.0.2 for interoperability */
+ private static final long serialVersionUID = -6849794470754667710L;
+
+ /**
+ * If String compaction is disabled, the bytes in {@code value} are
+ * always encoded in UTF16.
+ *
+ * For methods with several possible implementation paths, when String
+ * compaction is disabled, only one code path is taken.
+ *
+ * The instance field value is generally opaque to optimizing JIT
+ * compilers. Therefore, in performance-sensitive place, an explicit
+ * check of the static boolean {@code COMPACT_STRINGS} is done first
+ * before checking the {@code coder} field since the static boolean
+ * {@code COMPACT_STRINGS} would be constant folded away by an
+ * optimizing JIT compiler. The idioms for these cases are as follows.
+ *
+ * For code such as:
+ *
+ * if (coder == LATIN1) { ... }
+ *
+ * can be written more optimally as
+ *
+ * if (coder() == LATIN1) { ... }
+ *
+ * or:
+ *
+ * if (COMPACT_STRINGS && coder == LATIN1) { ... }
+ *
+ * An optimizing JIT compiler can fold the above conditional as:
+ *
+ * COMPACT_STRINGS == true => if (coder == LATIN1) { ... }
+ * COMPACT_STRINGS == false => if (false) { ... }
+ *
+ * @implNote
+ * The actual value for this field is injected by JVM. The static
+ * initialization block is used to set the value here to communicate
+ * that this static final field is not statically foldable, and to
+ * avoid any possible circular dependency during vm initialization.
+ */
+ static final boolean COMPACT_STRINGS;
+
+ static {
+ COMPACT_STRINGS = true;
+ }
+
+ /**
+ * Class String is special cased within the Serialization Stream Protocol.
+ *
+ * A String instance is written into an ObjectOutputStream according to
+ * <a href="{@docRoot}/../specs/serialization/protocol.html#stream-elements">
+ * Object Serialization Specification, Section 6.2, "Stream Elements"</a>
+ */
+ private static final ObjectStreamField[] serialPersistentFields =
+ new ObjectStreamField[0];
+
+ /**
+ * Initializes a newly created {@code String} object so that it represents
+ * an empty character sequence. Note that use of this constructor is
+ * unnecessary since Strings are immutable.
+ */
+ public String() {
+ this.value = "".value;
+ this.coder = "".coder;
+ }
+
+ /**
+ * Initializes a newly created {@code String} object so that it represents
+ * the same sequence of characters as the argument; in other words, the
+ * newly created string is a copy of the argument string. Unless an
+ * explicit copy of {@code original} is needed, use of this constructor is
+ * unnecessary since Strings are immutable.
+ *
+ * @param original
+ * A {@code String}
+ */
+ @HotSpotIntrinsicCandidate
+ public String(String original) {
+ this.value = original.value;
+ this.coder = original.coder;
+ this.hash = original.hash;
+ }
+
+ /**
+ * Allocates a new {@code String} so that it represents the sequence of
+ * characters currently contained in the character array argument. The
+ * contents of the character array are copied; subsequent modification of
+ * the character array does not affect the newly created string.
+ *
+ * @param value
+ * The initial value of the string
+ */
+ public String(char value[]) {
+ this(value, 0, value.length, null);
+ }
+
+ /**
+ * Allocates a new {@code String} that contains characters from a subarray
+ * of the character array argument. The {@code offset} argument is the
+ * index of the first character of the subarray and the {@code count}
+ * argument specifies the length of the subarray. The contents of the
+ * subarray are copied; subsequent modification of the character array does
+ * not affect the newly created string.
+ *
+ * @param value
+ * Array that is the source of characters
+ *
+ * @param offset
+ * The initial offset
+ *
+ * @param count
+ * The length
+ *
+ * @throws IndexOutOfBoundsException
+ * If {@code offset} is negative, {@code count} is negative, or
+ * {@code offset} is greater than {@code value.length - count}
+ */
+ public String(char value[], int offset, int count) {
+ this(value, offset, count, rangeCheck(value, offset, count));
+ }
+
+ private static Void rangeCheck(char[] value, int offset, int count) {
+ checkBoundsOffCount(offset, count, value.length);
+ return null;
+ }
+
+ /**
+ * Allocates a new {@code String} that contains characters from a subarray
+ * of the <a href="Character.html#unicode">Unicode code point</a> array
+ * argument. The {@code offset} argument is the index of the first code
+ * point of the subarray and the {@code count} argument specifies the
+ * length of the subarray. The contents of the subarray are converted to
+ * {@code char}s; subsequent modification of the {@code int} array does not
+ * affect the newly created string.
+ *
+ * @param codePoints
+ * Array that is the source of Unicode code points
+ *
+ * @param offset
+ * The initial offset
+ *
+ * @param count
+ * The length
+ *
+ * @throws IllegalArgumentException
+ * If any invalid Unicode code point is found in {@code
+ * codePoints}
+ *
+ * @throws IndexOutOfBoundsException
+ * If {@code offset} is negative, {@code count} is negative, or
+ * {@code offset} is greater than {@code codePoints.length - count}
+ *
+ * @since 1.5
+ */
+ public String(int[] codePoints, int offset, int count) {
+ checkBoundsOffCount(offset, count, codePoints.length);
+ if (count == 0) {
+ this.value = "".value;
+ this.coder = "".coder;
+ return;
+ }
+ if (COMPACT_STRINGS) {
+ byte[] val = StringLatin1.toBytes(codePoints, offset, count);
+ if (val != null) {
+ this.coder = LATIN1;
+ this.value = val;
+ return;
+ }
+ }
+ this.coder = UTF16;
+ this.value = StringUTF16.toBytes(codePoints, offset, count);
+ }
+
+ /**
+ * Allocates a new {@code String} constructed from a subarray of an array
+ * of 8-bit integer values.
+ *
+ * <p> The {@code offset} argument is the index of the first byte of the
+ * subarray, and the {@code count} argument specifies the length of the
+ * subarray.
+ *
+ * <p> Each {@code byte} in the subarray is converted to a {@code char} as
+ * specified in the {@link #String(byte[],int) String(byte[],int)} constructor.
+ *
+ * @deprecated This method does not properly convert bytes into characters.
+ * As of JDK 1.1, the preferred way to do this is via the
+ * {@code String} constructors that take a {@link
+ * java.nio.charset.Charset}, charset name, or that use the platform's
+ * default charset.
+ *
+ * @param ascii
+ * The bytes to be converted to characters
+ *
+ * @param hibyte
+ * The top 8 bits of each 16-bit Unicode code unit
+ *
+ * @param offset
+ * The initial offset
+ * @param count
+ * The length
+ *
+ * @throws IndexOutOfBoundsException
+ * If {@code offset} is negative, {@code count} is negative, or
+ * {@code offset} is greater than {@code ascii.length - count}
+ *
+ * @see #String(byte[], int)
+ * @see #String(byte[], int, int, java.lang.String)
+ * @see #String(byte[], int, int, java.nio.charset.Charset)
+ * @see #String(byte[], int, int)
+ * @see #String(byte[], java.lang.String)
+ * @see #String(byte[], java.nio.charset.Charset)
+ * @see #String(byte[])
+ */
+ @Deprecated(since="1.1")
+ public String(byte ascii[], int hibyte, int offset, int count) {
+ checkBoundsOffCount(offset, count, ascii.length);
+ if (count == 0) {
+ this.value = "".value;
+ this.coder = "".coder;
+ return;
+ }
+ if (COMPACT_STRINGS && (byte)hibyte == 0) {
+ this.value = Arrays.copyOfRange(ascii, offset, offset + count);
+ this.coder = LATIN1;
+ } else {
+ hibyte <<= 8;
+ byte[] val = StringUTF16.newBytesFor(count);
+ for (int i = 0; i < count; i++) {
+ StringUTF16.putChar(val, i, hibyte | (ascii[offset++] & 0xff));
+ }
+ this.value = val;
+ this.coder = UTF16;
+ }
+ }
+
+ /**
+ * Allocates a new {@code String} containing characters constructed from
+ * an array of 8-bit integer values. Each character <i>c</i> in the
+ * resulting string is constructed from the corresponding component
+ * <i>b</i> in the byte array such that:
+ *
+ * <blockquote><pre>
+ * <b><i>c</i></b> == (char)(((hibyte & 0xff) << 8)
+ * | (<b><i>b</i></b> & 0xff))
+ * </pre></blockquote>
+ *
+ * @deprecated This method does not properly convert bytes into
+ * characters. As of JDK 1.1, the preferred way to do this is via the
+ * {@code String} constructors that take a {@link
+ * java.nio.charset.Charset}, charset name, or that use the platform's
+ * default charset.
+ *
+ * @param ascii
+ * The bytes to be converted to characters
+ *
+ * @param hibyte
+ * The top 8 bits of each 16-bit Unicode code unit
+ *
+ * @see #String(byte[], int, int, java.lang.String)
+ * @see #String(byte[], int, int, java.nio.charset.Charset)
+ * @see #String(byte[], int, int)
+ * @see #String(byte[], java.lang.String)
+ * @see #String(byte[], java.nio.charset.Charset)
+ * @see #String(byte[])
+ */
+ @Deprecated(since="1.1")
+ public String(byte ascii[], int hibyte) {
+ this(ascii, hibyte, 0, ascii.length);
+ }
+
+ /**
+ * Constructs a new {@code String} by decoding the specified subarray of
+ * bytes using the specified charset. The length of the new {@code String}
+ * is a function of the charset, and hence may not be equal to the length
+ * of the subarray.
+ *
+ * <p> The behavior of this constructor when the given bytes are not valid
+ * in the given charset is unspecified. The {@link
+ * java.nio.charset.CharsetDecoder} class should be used when more control
+ * over the decoding process is required.
+ *
+ * @param bytes
+ * The bytes to be decoded into characters
+ *
+ * @param offset
+ * The index of the first byte to decode
+ *
+ * @param length
+ * The number of bytes to decode
+
+ * @param charsetName
+ * The name of a supported {@linkplain java.nio.charset.Charset
+ * charset}
+ *
+ * @throws UnsupportedEncodingException
+ * If the named charset is not supported
+ *
+ * @throws IndexOutOfBoundsException
+ * If {@code offset} is negative, {@code length} is negative, or
+ * {@code offset} is greater than {@code bytes.length - length}
+ *
+ * @since 1.1
+ */
+ public String(byte bytes[], int offset, int length, String charsetName)
+ throws UnsupportedEncodingException {
+ if (charsetName == null)
+ throw new NullPointerException("charsetName");
+ checkBoundsOffCount(offset, length, bytes.length);
+ StringCoding.Result ret =
+ StringCoding.decode(charsetName, bytes, offset, length);
+ this.value = ret.value;
+ this.coder = ret.coder;
+ }
+
+ /**
+ * Constructs a new {@code String} by decoding the specified subarray of
+ * bytes using the specified {@linkplain java.nio.charset.Charset charset}.
+ * The length of the new {@code String} is a function of the charset, and
+ * hence may not be equal to the length of the subarray.
+ *
+ * <p> This method always replaces malformed-input and unmappable-character
+ * sequences with this charset's default replacement string. The {@link
+ * java.nio.charset.CharsetDecoder} class should be used when more control
+ * over the decoding process is required.
+ *
+ * @param bytes
+ * The bytes to be decoded into characters
+ *
+ * @param offset
+ * The index of the first byte to decode
+ *
+ * @param length
+ * The number of bytes to decode
+ *
+ * @param charset
+ * The {@linkplain java.nio.charset.Charset charset} to be used to
+ * decode the {@code bytes}
+ *
+ * @throws IndexOutOfBoundsException
+ * If {@code offset} is negative, {@code length} is negative, or
+ * {@code offset} is greater than {@code bytes.length - length}
+ *
+ * @since 1.6
+ */
+ public String(byte bytes[], int offset, int length, Charset charset) {
+ if (charset == null)
+ throw new NullPointerException("charset");
+ checkBoundsOffCount(offset, length, bytes.length);
+ StringCoding.Result ret =
+ StringCoding.decode(charset, bytes, offset, length);
+ this.value = ret.value;
+ this.coder = ret.coder;
+ }
+
+ /**
+ * Constructs a new {@code String} by decoding the specified array of bytes
+ * using the specified {@linkplain java.nio.charset.Charset charset}. The
+ * length of the new {@code String} is a function of the charset, and hence
+ * may not be equal to the length of the byte array.
+ *
+ * <p> The behavior of this constructor when the given bytes are not valid
+ * in the given charset is unspecified. The {@link
+ * java.nio.charset.CharsetDecoder} class should be used when more control
+ * over the decoding process is required.
+ *
+ * @param bytes
+ * The bytes to be decoded into characters
+ *
+ * @param charsetName
+ * The name of a supported {@linkplain java.nio.charset.Charset
+ * charset}
+ *
+ * @throws UnsupportedEncodingException
+ * If the named charset is not supported
+ *
+ * @since 1.1
+ */
+ public String(byte bytes[], String charsetName)
+ throws UnsupportedEncodingException {
+ this(bytes, 0, bytes.length, charsetName);
+ }
+
+ /**
+ * Constructs a new {@code String} by decoding the specified array of
+ * bytes using the specified {@linkplain java.nio.charset.Charset charset}.
+ * The length of the new {@code String} is a function of the charset, and
+ * hence may not be equal to the length of the byte array.
+ *
+ * <p> This method always replaces malformed-input and unmappable-character
+ * sequences with this charset's default replacement string. The {@link
+ * java.nio.charset.CharsetDecoder} class should be used when more control
+ * over the decoding process is required.
+ *
+ * @param bytes
+ * The bytes to be decoded into characters
+ *
+ * @param charset
+ * The {@linkplain java.nio.charset.Charset charset} to be used to
+ * decode the {@code bytes}
+ *
+ * @since 1.6
+ */
+ public String(byte bytes[], Charset charset) {
+ this(bytes, 0, bytes.length, charset);
+ }
+
+ /**
+ * Constructs a new {@code String} by decoding the specified subarray of
+ * bytes using the platform's default charset. The length of the new
+ * {@code String} is a function of the charset, and hence may not be equal
+ * to the length of the subarray.
+ *
+ * <p> The behavior of this constructor when the given bytes are not valid
+ * in the default charset is unspecified. The {@link
+ * java.nio.charset.CharsetDecoder} class should be used when more control
+ * over the decoding process is required.
+ *
+ * @param bytes
+ * The bytes to be decoded into characters
+ *
+ * @param offset
+ * The index of the first byte to decode
+ *
+ * @param length
+ * The number of bytes to decode
+ *
+ * @throws IndexOutOfBoundsException
+ * If {@code offset} is negative, {@code length} is negative, or
+ * {@code offset} is greater than {@code bytes.length - length}
+ *
+ * @since 1.1
+ */
+ public String(byte bytes[], int offset, int length) {
+ checkBoundsOffCount(offset, length, bytes.length);
+ StringCoding.Result ret = StringCoding.decode(bytes, offset, length);
+ this.value = ret.value;
+ this.coder = ret.coder;
+ }
+
+ /**
+ * Constructs a new {@code String} by decoding the specified array of bytes
+ * using the platform's default charset. The length of the new {@code
+ * String} is a function of the charset, and hence may not be equal to the
+ * length of the byte array.
+ *
+ * <p> The behavior of this constructor when the given bytes are not valid
+ * in the default charset is unspecified. The {@link
+ * java.nio.charset.CharsetDecoder} class should be used when more control
+ * over the decoding process is required.
+ *
+ * @param bytes
+ * The bytes to be decoded into characters
+ *
+ * @since 1.1
+ */
+ public String(byte[] bytes) {
+ this(bytes, 0, bytes.length);
+ }
+
+ /**
+ * Allocates a new string that contains the sequence of characters
+ * currently contained in the string buffer argument. The contents of the
+ * string buffer are copied; subsequent modification of the string buffer
+ * does not affect the newly created string.
+ *
+ * @param buffer
+ * A {@code StringBuffer}
+ */
+ public String(StringBuffer buffer) {
+ this(buffer.toString());
+ }
+
+ /**
+ * Allocates a new string that contains the sequence of characters
+ * currently contained in the string builder argument. The contents of the
+ * string builder are copied; subsequent modification of the string builder
+ * does not affect the newly created string.
+ *
+ * <p> This constructor is provided to ease migration to {@code
+ * StringBuilder}. Obtaining a string from a string builder via the {@code
+ * toString} method is likely to run faster and is generally preferred.
+ *
+ * @param builder
+ * A {@code StringBuilder}
+ *
+ * @since 1.5
+ */
+ public String(StringBuilder builder) {
+ this(builder, null);
+ }
+
+ /*
+ * Package private constructor which shares value array for speed.
+ * this constructor is always expected to be called with share==true.
+ * a separate constructor is needed because we already have a public
+ * String(char[]) constructor that makes a copy of the given char[].
+ */
+ // TBD: this is kept for package internal use (Thread/System),
+ // should be removed if they all have a byte[] version
+ String(char[] val, boolean share) {
+ // assert share : "unshared not supported";
+ this(val, 0, val.length, null);
+ }
+
+ /**
+ * Returns the length of this string.
+ * The length is equal to the number of <a href="Character.html#unicode">Unicode
+ * code units</a> in the string.
+ *
+ * @return the length of the sequence of characters represented by this
+ * object.
+ */
+ public int length() {
+ return value.length >> coder();
+ }
+
+ /**
+ * Returns {@code true} if, and only if, {@link #length()} is {@code 0}.
+ *
+ * @return {@code true} if {@link #length()} is {@code 0}, otherwise
+ * {@code false}
+ *
+ * @since 1.6
+ */
+ public boolean isEmpty() {
+ return value.length == 0;
+ }
+
+ /**
+ * Returns the {@code char} value at the
+ * specified index. An index ranges from {@code 0} to
+ * {@code length() - 1}. The first {@code char} value of the sequence
+ * is at index {@code 0}, the next at index {@code 1},
+ * and so on, as for array indexing.
+ *
+ * <p>If the {@code char} value specified by the index is a
+ * <a href="Character.html#unicode">surrogate</a>, the surrogate
+ * value is returned.
+ *
+ * @param index the index of the {@code char} value.
+ * @return the {@code char} value at the specified index of this string.
+ * The first {@code char} value is at index {@code 0}.
+ * @exception IndexOutOfBoundsException if the {@code index}
+ * argument is negative or not less than the length of this
+ * string.
+ */
+ public char charAt(int index) {
+ if (isLatin1()) {
+ return StringLatin1.charAt(value, index);
+ } else {
+ return StringUTF16.charAt(value, index);
+ }
+ }
+
+ /**
+ * Returns the character (Unicode code point) at the specified
+ * index. The index refers to {@code char} values
+ * (Unicode code units) and ranges from {@code 0} to
+ * {@link #length()}{@code - 1}.
+ *
+ * <p> If the {@code char} value specified at the given index
+ * is in the high-surrogate range, the following index is less
+ * than the length of this {@code String}, and the
+ * {@code char} value at the following index is in the
+ * low-surrogate range, then the supplementary code point
+ * corresponding to this surrogate pair is returned. Otherwise,
+ * the {@code char} value at the given index is returned.
+ *
+ * @param index the index to the {@code char} values
+ * @return the code point value of the character at the
+ * {@code index}
+ * @exception IndexOutOfBoundsException if the {@code index}
+ * argument is negative or not less than the length of this
+ * string.
+ * @since 1.5
+ */
+ public int codePointAt(int index) {
+ if (isLatin1()) {
+ checkIndex(index, value.length);
+ return value[index] & 0xff;
+ }
+ int length = value.length >> 1;
+ checkIndex(index, length);
+ return StringUTF16.codePointAt(value, index, length);
+ }
+
+ /**
+ * Returns the character (Unicode code point) before the specified
+ * index. The index refers to {@code char} values
+ * (Unicode code units) and ranges from {@code 1} to {@link
+ * CharSequence#length() length}.
+ *
+ * <p> If the {@code char} value at {@code (index - 1)}
+ * is in the low-surrogate range, {@code (index - 2)} is not
+ * negative, and the {@code char} value at {@code (index -
+ * 2)} is in the high-surrogate range, then the
+ * supplementary code point value of the surrogate pair is
+ * returned. If the {@code char} value at {@code index -
+ * 1} is an unpaired low-surrogate or a high-surrogate, the
+ * surrogate value is returned.
+ *
+ * @param index the index following the code point that should be returned
+ * @return the Unicode code point value before the given index.
+ * @exception IndexOutOfBoundsException if the {@code index}
+ * argument is less than 1 or greater than the length
+ * of this string.
+ * @since 1.5
+ */
+ public int codePointBefore(int index) {
+ int i = index - 1;
+ if (i < 0 || i >= length()) {
+ throw new StringIndexOutOfBoundsException(index);
+ }
+ if (isLatin1()) {
+ return (value[i] & 0xff);
+ }
+ return StringUTF16.codePointBefore(value, index);
+ }
+
+ /**
+ * Returns the number of Unicode code points in the specified text
+ * range of this {@code String}. The text range begins at the
+ * specified {@code beginIndex} and extends to the
+ * {@code char} at index {@code endIndex - 1}. Thus the
+ * length (in {@code char}s) of the text range is
+ * {@code endIndex-beginIndex}. Unpaired surrogates within
+ * the text range count as one code point each.
+ *
+ * @param beginIndex the index to the first {@code char} of
+ * the text range.
+ * @param endIndex the index after the last {@code char} of
+ * the text range.
+ * @return the number of Unicode code points in the specified text
+ * range
+ * @exception IndexOutOfBoundsException if the
+ * {@code beginIndex} is negative, or {@code endIndex}
+ * is larger than the length of this {@code String}, or
+ * {@code beginIndex} is larger than {@code endIndex}.
+ * @since 1.5
+ */
+ public int codePointCount(int beginIndex, int endIndex) {
+ if (beginIndex < 0 || beginIndex > endIndex ||
+ endIndex > length()) {
+ throw new IndexOutOfBoundsException();
+ }
+ if (isLatin1()) {
+ return endIndex - beginIndex;
+ }
+ return StringUTF16.codePointCount(value, beginIndex, endIndex);
+ }
+
+ /**
+ * Returns the index within this {@code String} that is
+ * offset from the given {@code index} by
+ * {@code codePointOffset} code points. Unpaired surrogates
+ * within the text range given by {@code index} and
+ * {@code codePointOffset} count as one code point each.
+ *
+ * @param index the index to be offset
+ * @param codePointOffset the offset in code points
+ * @return the index within this {@code String}
+ * @exception IndexOutOfBoundsException if {@code index}
+ * is negative or larger then the length of this
+ * {@code String}, or if {@code codePointOffset} is positive
+ * and the substring starting with {@code index} has fewer
+ * than {@code codePointOffset} code points,
+ * or if {@code codePointOffset} is negative and the substring
+ * before {@code index} has fewer than the absolute value
+ * of {@code codePointOffset} code points.
+ * @since 1.5
+ */
+ public int offsetByCodePoints(int index, int codePointOffset) {
+ if (index < 0 || index > length()) {
+ throw new IndexOutOfBoundsException();
+ }
+ return Character.offsetByCodePoints(this, index, codePointOffset);
+ }
+
+ /**
+ * Copies characters from this string into the destination character
+ * array.
+ * <p>
+ * The first character to be copied is at index {@code srcBegin};
+ * the last character to be copied is at index {@code srcEnd-1}
+ * (thus the total number of characters to be copied is
+ * {@code srcEnd-srcBegin}). The characters are copied into the
+ * subarray of {@code dst} starting at index {@code dstBegin}
+ * and ending at index:
+ * <blockquote><pre>
+ * dstBegin + (srcEnd-srcBegin) - 1
+ * </pre></blockquote>
+ *
+ * @param srcBegin index of the first character in the string
+ * to copy.
+ * @param srcEnd index after the last character in the string
+ * to copy.
+ * @param dst the destination array.
+ * @param dstBegin the start offset in the destination array.
+ * @exception IndexOutOfBoundsException If any of the following
+ * is true:
+ * <ul><li>{@code srcBegin} is negative.
+ * <li>{@code srcBegin} is greater than {@code srcEnd}
+ * <li>{@code srcEnd} is greater than the length of this
+ * string
+ * <li>{@code dstBegin} is negative
+ * <li>{@code dstBegin+(srcEnd-srcBegin)} is larger than
+ * {@code dst.length}</ul>
+ */
+ public void getChars(int srcBegin, int srcEnd, char dst[], int dstBegin) {
+ checkBoundsBeginEnd(srcBegin, srcEnd, length());
+ checkBoundsOffCount(dstBegin, srcEnd - srcBegin, dst.length);
+ if (isLatin1()) {
+ StringLatin1.getChars(value, srcBegin, srcEnd, dst, dstBegin);
+ } else {
+ StringUTF16.getChars(value, srcBegin, srcEnd, dst, dstBegin);
+ }
+ }
+
+ /**
+ * Copies characters from this string into the destination byte array. Each
+ * byte receives the 8 low-order bits of the corresponding character. The
+ * eight high-order bits of each character are not copied and do not
+ * participate in the transfer in any way.
+ *
+ * <p> The first character to be copied is at index {@code srcBegin}; the
+ * last character to be copied is at index {@code srcEnd-1}. The total
+ * number of characters to be copied is {@code srcEnd-srcBegin}. The
+ * characters, converted to bytes, are copied into the subarray of {@code
+ * dst} starting at index {@code dstBegin} and ending at index:
+ *
+ * <blockquote><pre>
+ * dstBegin + (srcEnd-srcBegin) - 1
+ * </pre></blockquote>
+ *
+ * @deprecated This method does not properly convert characters into
+ * bytes. As of JDK 1.1, the preferred way to do this is via the
+ * {@link #getBytes()} method, which uses the platform's default charset.
+ *
+ * @param srcBegin
+ * Index of the first character in the string to copy
+ *
+ * @param srcEnd
+ * Index after the last character in the string to copy
+ *
+ * @param dst
+ * The destination array
+ *
+ * @param dstBegin
+ * The start offset in the destination array
+ *
+ * @throws IndexOutOfBoundsException
+ * If any of the following is true:
+ * <ul>
+ * <li> {@code srcBegin} is negative
+ * <li> {@code srcBegin} is greater than {@code srcEnd}
+ * <li> {@code srcEnd} is greater than the length of this String
+ * <li> {@code dstBegin} is negative
+ * <li> {@code dstBegin+(srcEnd-srcBegin)} is larger than {@code
+ * dst.length}
+ * </ul>
+ */
+ @Deprecated(since="1.1")
+ public void getBytes(int srcBegin, int srcEnd, byte dst[], int dstBegin) {
+ checkBoundsBeginEnd(srcBegin, srcEnd, length());
+ Objects.requireNonNull(dst);
+ checkBoundsOffCount(dstBegin, srcEnd - srcBegin, dst.length);
+ if (isLatin1()) {
+ StringLatin1.getBytes(value, srcBegin, srcEnd, dst, dstBegin);
+ } else {
+ StringUTF16.getBytes(value, srcBegin, srcEnd, dst, dstBegin);
+ }
+ }
+
+ /**
+ * Encodes this {@code String} into a sequence of bytes using the named
+ * charset, storing the result into a new byte array.
+ *
+ * <p> The behavior of this method when this string cannot be encoded in
+ * the given charset is unspecified. The {@link
+ * java.nio.charset.CharsetEncoder} class should be used when more control
+ * over the encoding process is required.
+ *
+ * @param charsetName
+ * The name of a supported {@linkplain java.nio.charset.Charset
+ * charset}
+ *
+ * @return The resultant byte array
+ *
+ * @throws UnsupportedEncodingException
+ * If the named charset is not supported
+ *
+ * @since 1.1
+ */
+ public byte[] getBytes(String charsetName)
+ throws UnsupportedEncodingException {
+ if (charsetName == null) throw new NullPointerException();
+ return StringCoding.encode(charsetName, coder(), value);
+ }
+
+ /**
+ * Encodes this {@code String} into a sequence of bytes using the given
+ * {@linkplain java.nio.charset.Charset charset}, storing the result into a
+ * new byte array.
+ *
+ * <p> This method always replaces malformed-input and unmappable-character
+ * sequences with this charset's default replacement byte array. The
+ * {@link java.nio.charset.CharsetEncoder} class should be used when more
+ * control over the encoding process is required.
+ *
+ * @param charset
+ * The {@linkplain java.nio.charset.Charset} to be used to encode
+ * the {@code String}
+ *
+ * @return The resultant byte array
+ *
+ * @since 1.6
+ */
+ public byte[] getBytes(Charset charset) {
+ if (charset == null) throw new NullPointerException();
+ return StringCoding.encode(charset, coder(), value);
+ }
+
+ /**
+ * Encodes this {@code String} into a sequence of bytes using the
+ * platform's default charset, storing the result into a new byte array.
+ *
+ * <p> The behavior of this method when this string cannot be encoded in
+ * the default charset is unspecified. The {@link
+ * java.nio.charset.CharsetEncoder} class should be used when more control
+ * over the encoding process is required.
+ *
+ * @return The resultant byte array
+ *
+ * @since 1.1
+ */
+ public byte[] getBytes() {
+ return StringCoding.encode(coder(), value);
+ }
+
+ /**
+ * Compares this string to the specified object. The result is {@code
+ * true} if and only if the argument is not {@code null} and is a {@code
+ * String} object that represents the same sequence of characters as this
+ * object.
+ *
+ * <p>For finer-grained String comparison, refer to
+ * {@link java.text.Collator}.
+ *
+ * @param anObject
+ * The object to compare this {@code String} against
+ *
+ * @return {@code true} if the given object represents a {@code String}
+ * equivalent to this string, {@code false} otherwise
+ *
+ * @see #compareTo(String)
+ * @see #equalsIgnoreCase(String)
+ */
+ public boolean equals(Object anObject) {
+ if (this == anObject) {
+ return true;
+ }
+ if (anObject instanceof String) {
+ String aString = (String)anObject;
+ if (coder() == aString.coder()) {
+ return isLatin1() ? StringLatin1.equals(value, aString.value)
+ : StringUTF16.equals(value, aString.value);
+ }
+ }
+ return false;
+ }
+
+ /**
+ * Compares this string to the specified {@code StringBuffer}. The result
+ * is {@code true} if and only if this {@code String} represents the same
+ * sequence of characters as the specified {@code StringBuffer}. This method
+ * synchronizes on the {@code StringBuffer}.
+ *
+ * <p>For finer-grained String comparison, refer to
+ * {@link java.text.Collator}.
+ *
+ * @param sb
+ * The {@code StringBuffer} to compare this {@code String} against
+ *
+ * @return {@code true} if this {@code String} represents the same
+ * sequence of characters as the specified {@code StringBuffer},
+ * {@code false} otherwise
+ *
+ * @since 1.4
+ */
+ public boolean contentEquals(StringBuffer sb) {
+ return contentEquals((CharSequence)sb);
+ }
+
+ private boolean nonSyncContentEquals(AbstractStringBuilder sb) {
+ int len = length();
+ if (len != sb.length()) {
+ return false;
+ }
+ byte v1[] = value;
+ byte v2[] = sb.getValue();
+ if (coder() == sb.getCoder()) {
+ int n = v1.length;
+ for (int i = 0; i < n; i++) {
+ if (v1[i] != v2[i]) {
+ return false;
+ }
+ }
+ } else {
+ if (!isLatin1()) { // utf16 str and latin1 abs can never be "equal"
+ return false;
+ }
+ return StringUTF16.contentEquals(v1, v2, len);
+ }
+ return true;
+ }
+
+ /**
+ * Compares this string to the specified {@code CharSequence}. The
+ * result is {@code true} if and only if this {@code String} represents the
+ * same sequence of char values as the specified sequence. Note that if the
+ * {@code CharSequence} is a {@code StringBuffer} then the method
+ * synchronizes on it.
+ *
+ * <p>For finer-grained String comparison, refer to
+ * {@link java.text.Collator}.
+ *
+ * @param cs
+ * The sequence to compare this {@code String} against
+ *
+ * @return {@code true} if this {@code String} represents the same
+ * sequence of char values as the specified sequence, {@code
+ * false} otherwise
+ *
+ * @since 1.5
+ */
+ public boolean contentEquals(CharSequence cs) {
+ // Argument is a StringBuffer, StringBuilder
+ if (cs instanceof AbstractStringBuilder) {
+ if (cs instanceof StringBuffer) {
+ synchronized(cs) {
+ return nonSyncContentEquals((AbstractStringBuilder)cs);
+ }
+ } else {
+ return nonSyncContentEquals((AbstractStringBuilder)cs);
+ }
+ }
+ // Argument is a String
+ if (cs instanceof String) {
+ return equals(cs);
+ }
+ // Argument is a generic CharSequence
+ int n = cs.length();
+ if (n != length()) {
+ return false;
+ }
+ byte[] val = this.value;
+ if (isLatin1()) {
+ for (int i = 0; i < n; i++) {
+ if ((val[i] & 0xff) != cs.charAt(i)) {
+ return false;
+ }
+ }
+ } else {
+ if (!StringUTF16.contentEquals(val, cs, n)) {
+ return false;
+ }
+ }
+ return true;
+ }
+
+ /**
+ * Compares this {@code String} to another {@code String}, ignoring case
+ * considerations. Two strings are considered equal ignoring case if they
+ * are of the same length and corresponding characters in the two strings
+ * are equal ignoring case.
+ *
+ * <p> Two characters {@code c1} and {@code c2} are considered the same
+ * ignoring case if at least one of the following is true:
+ * <ul>
+ * <li> The two characters are the same (as compared by the
+ * {@code ==} operator)
+ * <li> Calling {@code Character.toLowerCase(Character.toUpperCase(char))}
+ * on each character produces the same result
+ * </ul>
+ *
+ * <p>Note that this method does <em>not</em> take locale into account, and
+ * will result in unsatisfactory results for certain locales. The
+ * {@link java.text.Collator} class provides locale-sensitive comparison.
+ *
+ * @param anotherString
+ * The {@code String} to compare this {@code String} against
+ *
+ * @return {@code true} if the argument is not {@code null} and it
+ * represents an equivalent {@code String} ignoring case; {@code
+ * false} otherwise
+ *
+ * @see #equals(Object)
+ */
+ public boolean equalsIgnoreCase(String anotherString) {
+ return (this == anotherString) ? true
+ : (anotherString != null)
+ && (anotherString.length() == length())
+ && regionMatches(true, 0, anotherString, 0, length());
+ }
+
+ /**
+ * Compares two strings lexicographically.
+ * The comparison is based on the Unicode value of each character in
+ * the strings. The character sequence represented by this
+ * {@code String} object is compared lexicographically to the
+ * character sequence represented by the argument string. The result is
+ * a negative integer if this {@code String} object
+ * lexicographically precedes the argument string. The result is a
+ * positive integer if this {@code String} object lexicographically
+ * follows the argument string. The result is zero if the strings
+ * are equal; {@code compareTo} returns {@code 0} exactly when
+ * the {@link #equals(Object)} method would return {@code true}.
+ * <p>
+ * This is the definition of lexicographic ordering. If two strings are
+ * different, then either they have different characters at some index
+ * that is a valid index for both strings, or their lengths are different,
+ * or both. If they have different characters at one or more index
+ * positions, let <i>k</i> be the smallest such index; then the string
+ * whose character at position <i>k</i> has the smaller value, as
+ * determined by using the {@code <} operator, lexicographically precedes the
+ * other string. In this case, {@code compareTo} returns the
+ * difference of the two character values at position {@code k} in
+ * the two string -- that is, the value:
+ * <blockquote><pre>
+ * this.charAt(k)-anotherString.charAt(k)
+ * </pre></blockquote>
+ * If there is no index position at which they differ, then the shorter
+ * string lexicographically precedes the longer string. In this case,
+ * {@code compareTo} returns the difference of the lengths of the
+ * strings -- that is, the value:
+ * <blockquote><pre>
+ * this.length()-anotherString.length()
+ * </pre></blockquote>
+ *
+ * <p>For finer-grained String comparison, refer to
+ * {@link java.text.Collator}.
+ *
+ * @param anotherString the {@code String} to be compared.
+ * @return the value {@code 0} if the argument string is equal to
+ * this string; a value less than {@code 0} if this string
+ * is lexicographically less than the string argument; and a
+ * value greater than {@code 0} if this string is
+ * lexicographically greater than the string argument.
+ */
+ public int compareTo(String anotherString) {
+ byte v1[] = value;
+ byte v2[] = anotherString.value;
+ if (coder() == anotherString.coder()) {
+ return isLatin1() ? StringLatin1.compareTo(v1, v2)
+ : StringUTF16.compareTo(v1, v2);
+ }
+ return isLatin1() ? StringLatin1.compareToUTF16(v1, v2)
+ : StringUTF16.compareToLatin1(v1, v2);
+ }
+
+ /**
+ * A Comparator that orders {@code String} objects as by
+ * {@code compareToIgnoreCase}. This comparator is serializable.
+ * <p>
+ * Note that this Comparator does <em>not</em> take locale into account,
+ * and will result in an unsatisfactory ordering for certain locales.
+ * The {@link java.text.Collator} class provides locale-sensitive comparison.
+ *
+ * @see java.text.Collator
+ * @since 1.2
+ */
+ public static final Comparator<String> CASE_INSENSITIVE_ORDER
+ = new CaseInsensitiveComparator();
+ private static class CaseInsensitiveComparator
+ implements Comparator<String>, java.io.Serializable {
+ // use serialVersionUID from JDK 1.2.2 for interoperability
+ private static final long serialVersionUID = 8575799808933029326L;
+
+ public int compare(String s1, String s2) {
+ byte v1[] = s1.value;
+ byte v2[] = s2.value;
+ if (s1.coder() == s2.coder()) {
+ return s1.isLatin1() ? StringLatin1.compareToCI(v1, v2)
+ : StringUTF16.compareToCI(v1, v2);
+ }
+ return s1.isLatin1() ? StringLatin1.compareToCI_UTF16(v1, v2)
+ : StringUTF16.compareToCI_Latin1(v1, v2);
+ }
+
+ /** Replaces the de-serialized object. */
+ private Object readResolve() { return CASE_INSENSITIVE_ORDER; }
+ }
+
+ /**
+ * Compares two strings lexicographically, ignoring case
+ * differences. This method returns an integer whose sign is that of
+ * calling {@code compareTo} with normalized versions of the strings
+ * where case differences have been eliminated by calling
+ * {@code Character.toLowerCase(Character.toUpperCase(character))} on
+ * each character.
+ * <p>
+ * Note that this method does <em>not</em> take locale into account,
+ * and will result in an unsatisfactory ordering for certain locales.
+ * The {@link java.text.Collator} class provides locale-sensitive comparison.
+ *
+ * @param str the {@code String} to be compared.
+ * @return a negative integer, zero, or a positive integer as the
+ * specified String is greater than, equal to, or less
+ * than this String, ignoring case considerations.
+ * @see java.text.Collator
+ * @since 1.2
+ */
+ public int compareToIgnoreCase(String str) {
+ return CASE_INSENSITIVE_ORDER.compare(this, str);
+ }
+
+ /**
+ * Tests if two string regions are equal.
+ * <p>
+ * A substring of this {@code String} object is compared to a substring
+ * of the argument other. The result is true if these substrings
+ * represent identical character sequences. The substring of this
+ * {@code String} object to be compared begins at index {@code toffset}
+ * and has length {@code len}. The substring of other to be compared
+ * begins at index {@code ooffset} and has length {@code len}. The
+ * result is {@code false} if and only if at least one of the following
+ * is true:
+ * <ul><li>{@code toffset} is negative.
+ * <li>{@code ooffset} is negative.
+ * <li>{@code toffset+len} is greater than the length of this
+ * {@code String} object.
+ * <li>{@code ooffset+len} is greater than the length of the other
+ * argument.
+ * <li>There is some nonnegative integer <i>k</i> less than {@code len}
+ * such that:
+ * {@code this.charAt(toffset + }<i>k</i>{@code ) != other.charAt(ooffset + }
+ * <i>k</i>{@code )}
+ * </ul>
+ *
+ * <p>Note that this method does <em>not</em> take locale into account. The
+ * {@link java.text.Collator} class provides locale-sensitive comparison.
+ *
+ * @param toffset the starting offset of the subregion in this string.
+ * @param other the string argument.
+ * @param ooffset the starting offset of the subregion in the string
+ * argument.
+ * @param len the number of characters to compare.
+ * @return {@code true} if the specified subregion of this string
+ * exactly matches the specified subregion of the string argument;
+ * {@code false} otherwise.
+ */
+ public boolean regionMatches(int toffset, String other, int ooffset, int len) {
+ byte tv[] = value;
+ byte ov[] = other.value;
+ // Note: toffset, ooffset, or len might be near -1>>>1.
+ if ((ooffset < 0) || (toffset < 0) ||
+ (toffset > (long)length() - len) ||
+ (ooffset > (long)other.length() - len)) {
+ return false;
+ }
+ if (coder() == other.coder()) {
+ if (!isLatin1() && (len > 0)) {
+ toffset = toffset << 1;
+ ooffset = ooffset << 1;
+ len = len << 1;
+ }
+ while (len-- > 0) {
+ if (tv[toffset++] != ov[ooffset++]) {
+ return false;
+ }
+ }
+ } else {
+ if (coder() == LATIN1) {
+ while (len-- > 0) {
+ if (StringLatin1.getChar(tv, toffset++) !=
+ StringUTF16.getChar(ov, ooffset++)) {
+ return false;
+ }
+ }
+ } else {
+ while (len-- > 0) {
+ if (StringUTF16.getChar(tv, toffset++) !=
+ StringLatin1.getChar(ov, ooffset++)) {
+ return false;
+ }
+ }
+ }
+ }
+ return true;
+ }
+
+ /**
+ * Tests if two string regions are equal.
+ * <p>
+ * A substring of this {@code String} object is compared to a substring
+ * of the argument {@code other}. The result is {@code true} if these
+ * substrings represent character sequences that are the same, ignoring
+ * case if and only if {@code ignoreCase} is true. The substring of
+ * this {@code String} object to be compared begins at index
+ * {@code toffset} and has length {@code len}. The substring of
+ * {@code other} to be compared begins at index {@code ooffset} and
+ * has length {@code len}. The result is {@code false} if and only if
+ * at least one of the following is true:
+ * <ul><li>{@code toffset} is negative.
+ * <li>{@code ooffset} is negative.
+ * <li>{@code toffset+len} is greater than the length of this
+ * {@code String} object.
+ * <li>{@code ooffset+len} is greater than the length of the other
+ * argument.
+ * <li>{@code ignoreCase} is {@code false} and there is some nonnegative
+ * integer <i>k</i> less than {@code len} such that:
+ * <blockquote><pre>
+ * this.charAt(toffset+k) != other.charAt(ooffset+k)
+ * </pre></blockquote>
+ * <li>{@code ignoreCase} is {@code true} and there is some nonnegative
+ * integer <i>k</i> less than {@code len} such that:
+ * <blockquote><pre>
+ * Character.toLowerCase(Character.toUpperCase(this.charAt(toffset+k))) !=
+ Character.toLowerCase(Character.toUpperCase(other.charAt(ooffset+k)))
+ * </pre></blockquote>
+ * </ul>
+ *
+ * <p>Note that this method does <em>not</em> take locale into account,
+ * and will result in unsatisfactory results for certain locales when
+ * {@code ignoreCase} is {@code true}. The {@link java.text.Collator} class
+ * provides locale-sensitive comparison.
+ *
+ * @param ignoreCase if {@code true}, ignore case when comparing
+ * characters.
+ * @param toffset the starting offset of the subregion in this
+ * string.
+ * @param other the string argument.
+ * @param ooffset the starting offset of the subregion in the string
+ * argument.
+ * @param len the number of characters to compare.
+ * @return {@code true} if the specified subregion of this string
+ * matches the specified subregion of the string argument;
+ * {@code false} otherwise. Whether the matching is exact
+ * or case insensitive depends on the {@code ignoreCase}
+ * argument.
+ */
+ public boolean regionMatches(boolean ignoreCase, int toffset,
+ String other, int ooffset, int len) {
+ if (!ignoreCase) {
+ return regionMatches(toffset, other, ooffset, len);
+ }
+ // Note: toffset, ooffset, or len might be near -1>>>1.
+ if ((ooffset < 0) || (toffset < 0)
+ || (toffset > (long)length() - len)
+ || (ooffset > (long)other.length() - len)) {
+ return false;
+ }
+ byte tv[] = value;
+ byte ov[] = other.value;
+ if (coder() == other.coder()) {
+ return isLatin1()
+ ? StringLatin1.regionMatchesCI(tv, toffset, ov, ooffset, len)
+ : StringUTF16.regionMatchesCI(tv, toffset, ov, ooffset, len);
+ }
+ return isLatin1()
+ ? StringLatin1.regionMatchesCI_UTF16(tv, toffset, ov, ooffset, len)
+ : StringUTF16.regionMatchesCI_Latin1(tv, toffset, ov, ooffset, len);
+ }
+
+ /**
+ * Tests if the substring of this string beginning at the
+ * specified index starts with the specified prefix.
+ *
+ * @param prefix the prefix.
+ * @param toffset where to begin looking in this string.
+ * @return {@code true} if the character sequence represented by the
+ * argument is a prefix of the substring of this object starting
+ * at index {@code toffset}; {@code false} otherwise.
+ * The result is {@code false} if {@code toffset} is
+ * negative or greater than the length of this
+ * {@code String} object; otherwise the result is the same
+ * as the result of the expression
+ * <pre>
+ * this.substring(toffset).startsWith(prefix)
+ * </pre>
+ */
+ public boolean startsWith(String prefix, int toffset) {
+ // Note: toffset might be near -1>>>1.
+ if (toffset < 0 || toffset > length() - prefix.length()) {
+ return false;
+ }
+ byte ta[] = value;
+ byte pa[] = prefix.value;
+ int po = 0;
+ int pc = pa.length;
+ if (coder() == prefix.coder()) {
+ int to = isLatin1() ? toffset : toffset << 1;
+ while (po < pc) {
+ if (ta[to++] != pa[po++]) {
+ return false;
+ }
+ }
+ } else {
+ if (isLatin1()) { // && pcoder == UTF16
+ return false;
+ }
+ // coder == UTF16 && pcoder == LATIN1)
+ while (po < pc) {
+ if (StringUTF16.getChar(ta, toffset++) != (pa[po++] & 0xff)) {
+ return false;
+ }
+ }
+ }
+ return true;
+ }
+
+ /**
+ * Tests if this string starts with the specified prefix.
+ *
+ * @param prefix the prefix.
+ * @return {@code true} if the character sequence represented by the
+ * argument is a prefix of the character sequence represented by
+ * this string; {@code false} otherwise.
+ * Note also that {@code true} will be returned if the
+ * argument is an empty string or is equal to this
+ * {@code String} object as determined by the
+ * {@link #equals(Object)} method.
+ * @since 1.0
+ */
+ public boolean startsWith(String prefix) {
+ return startsWith(prefix, 0);
+ }
+
+ /**
+ * Tests if this string ends with the specified suffix.
+ *
+ * @param suffix the suffix.
+ * @return {@code true} if the character sequence represented by the
+ * argument is a suffix of the character sequence represented by
+ * this object; {@code false} otherwise. Note that the
+ * result will be {@code true} if the argument is the
+ * empty string or is equal to this {@code String} object
+ * as determined by the {@link #equals(Object)} method.
+ */
+ public boolean endsWith(String suffix) {
+ return startsWith(suffix, length() - suffix.length());
+ }
+
+ /**
+ * Returns a hash code for this string. The hash code for a
+ * {@code String} object is computed as
+ * <blockquote><pre>
+ * s[0]*31^(n-1) + s[1]*31^(n-2) + ... + s[n-1]
+ * </pre></blockquote>
+ * using {@code int} arithmetic, where {@code s[i]} is the
+ * <i>i</i>th character of the string, {@code n} is the length of
+ * the string, and {@code ^} indicates exponentiation.
+ * (The hash value of the empty string is zero.)
+ *
+ * @return a hash code value for this object.
+ */
+ public int hashCode() {
+ int h = hash;
+ if (h == 0 && value.length > 0) {
+ hash = h = isLatin1() ? StringLatin1.hashCode(value)
+ : StringUTF16.hashCode(value);
+ }
+ return h;
+ }
+
+ /**
+ * Returns the index within this string of the first occurrence of
+ * the specified character. If a character with value
+ * {@code ch} occurs in the character sequence represented by
+ * this {@code String} object, then the index (in Unicode
+ * code units) of the first such occurrence is returned. For
+ * values of {@code ch} in the range from 0 to 0xFFFF
+ * (inclusive), this is the smallest value <i>k</i> such that:
+ * <blockquote><pre>
+ * this.charAt(<i>k</i>) == ch
+ * </pre></blockquote>
+ * is true. For other values of {@code ch}, it is the
+ * smallest value <i>k</i> such that:
+ * <blockquote><pre>
+ * this.codePointAt(<i>k</i>) == ch
+ * </pre></blockquote>
+ * is true. In either case, if no such character occurs in this
+ * string, then {@code -1} is returned.
+ *
+ * @param ch a character (Unicode code point).
+ * @return the index of the first occurrence of the character in the
+ * character sequence represented by this object, or
+ * {@code -1} if the character does not occur.
+ */
+ public int indexOf(int ch) {
+ return indexOf(ch, 0);
+ }
+
+ /**
+ * Returns the index within this string of the first occurrence of the
+ * specified character, starting the search at the specified index.
+ * <p>
+ * If a character with value {@code ch} occurs in the
+ * character sequence represented by this {@code String}
+ * object at an index no smaller than {@code fromIndex}, then
+ * the index of the first such occurrence is returned. For values
+ * of {@code ch} in the range from 0 to 0xFFFF (inclusive),
+ * this is the smallest value <i>k</i> such that:
+ * <blockquote><pre>
+ * (this.charAt(<i>k</i>) == ch) {@code &&} (<i>k</i> >= fromIndex)
+ * </pre></blockquote>
+ * is true. For other values of {@code ch}, it is the
+ * smallest value <i>k</i> such that:
+ * <blockquote><pre>
+ * (this.codePointAt(<i>k</i>) == ch) {@code &&} (<i>k</i> >= fromIndex)
+ * </pre></blockquote>
+ * is true. In either case, if no such character occurs in this
+ * string at or after position {@code fromIndex}, then
+ * {@code -1} is returned.
+ *
+ * <p>
+ * There is no restriction on the value of {@code fromIndex}. If it
+ * is negative, it has the same effect as if it were zero: this entire
+ * string may be searched. If it is greater than the length of this
+ * string, it has the same effect as if it were equal to the length of
+ * this string: {@code -1} is returned.
+ *
+ * <p>All indices are specified in {@code char} values
+ * (Unicode code units).
+ *
+ * @param ch a character (Unicode code point).
+ * @param fromIndex the index to start the search from.
+ * @return the index of the first occurrence of the character in the
+ * character sequence represented by this object that is greater
+ * than or equal to {@code fromIndex}, or {@code -1}
+ * if the character does not occur.
+ */
+ public int indexOf(int ch, int fromIndex) {
+ return isLatin1() ? StringLatin1.indexOf(value, ch, fromIndex)
+ : StringUTF16.indexOf(value, ch, fromIndex);
+ }
+
+ /**
+ * Returns the index within this string of the last occurrence of
+ * the specified character. For values of {@code ch} in the
+ * range from 0 to 0xFFFF (inclusive), the index (in Unicode code
+ * units) returned is the largest value <i>k</i> such that:
+ * <blockquote><pre>
+ * this.charAt(<i>k</i>) == ch
+ * </pre></blockquote>
+ * is true. For other values of {@code ch}, it is the
+ * largest value <i>k</i> such that:
+ * <blockquote><pre>
+ * this.codePointAt(<i>k</i>) == ch
+ * </pre></blockquote>
+ * is true. In either case, if no such character occurs in this
+ * string, then {@code -1} is returned. The
+ * {@code String} is searched backwards starting at the last
+ * character.
+ *
+ * @param ch a character (Unicode code point).
+ * @return the index of the last occurrence of the character in the
+ * character sequence represented by this object, or
+ * {@code -1} if the character does not occur.
+ */
+ public int lastIndexOf(int ch) {
+ return lastIndexOf(ch, length() - 1);
+ }
+
+ /**
+ * Returns the index within this string of the last occurrence of
+ * the specified character, searching backward starting at the
+ * specified index. For values of {@code ch} in the range
+ * from 0 to 0xFFFF (inclusive), the index returned is the largest
+ * value <i>k</i> such that:
+ * <blockquote><pre>
+ * (this.charAt(<i>k</i>) == ch) {@code &&} (<i>k</i> <= fromIndex)
+ * </pre></blockquote>
+ * is true. For other values of {@code ch}, it is the
+ * largest value <i>k</i> such that:
+ * <blockquote><pre>
+ * (this.codePointAt(<i>k</i>) == ch) {@code &&} (<i>k</i> <= fromIndex)
+ * </pre></blockquote>
+ * is true. In either case, if no such character occurs in this
+ * string at or before position {@code fromIndex}, then
+ * {@code -1} is returned.
+ *
+ * <p>All indices are specified in {@code char} values
+ * (Unicode code units).
+ *
+ * @param ch a character (Unicode code point).
+ * @param fromIndex the index to start the search from. There is no
+ * restriction on the value of {@code fromIndex}. If it is
+ * greater than or equal to the length of this string, it has
+ * the same effect as if it were equal to one less than the
+ * length of this string: this entire string may be searched.
+ * If it is negative, it has the same effect as if it were -1:
+ * -1 is returned.
+ * @return the index of the last occurrence of the character in the
+ * character sequence represented by this object that is less
+ * than or equal to {@code fromIndex}, or {@code -1}
+ * if the character does not occur before that point.
+ */
+ public int lastIndexOf(int ch, int fromIndex) {
+ return isLatin1() ? StringLatin1.lastIndexOf(value, ch, fromIndex)
+ : StringUTF16.lastIndexOf(value, ch, fromIndex);
+ }
+
+ /**
+ * Returns the index within this string of the first occurrence of the
+ * specified substring.
+ *
+ * <p>The returned index is the smallest value {@code k} for which:
+ * <pre>{@code
+ * this.startsWith(str, k)
+ * }</pre>
+ * If no such value of {@code k} exists, then {@code -1} is returned.
+ *
+ * @param str the substring to search for.
+ * @return the index of the first occurrence of the specified substring,
+ * or {@code -1} if there is no such occurrence.
+ */
+ public int indexOf(String str) {
+ if (coder() == str.coder()) {
+ return isLatin1() ? StringLatin1.indexOf(value, str.value)
+ : StringUTF16.indexOf(value, str.value);
+ }
+ if (coder() == LATIN1) { // str.coder == UTF16
+ return -1;
+ }
+ return StringUTF16.indexOfLatin1(value, str.value);
+ }
+
+ /**
+ * Returns the index within this string of the first occurrence of the
+ * specified substring, starting at the specified index.
+ *
+ * <p>The returned index is the smallest value {@code k} for which:
+ * <pre>{@code
+ * k >= Math.min(fromIndex, this.length()) &&
+ * this.startsWith(str, k)
+ * }</pre>
+ * If no such value of {@code k} exists, then {@code -1} is returned.
+ *
+ * @param str the substring to search for.
+ * @param fromIndex the index from which to start the search.
+ * @return the index of the first occurrence of the specified substring,
+ * starting at the specified index,
+ * or {@code -1} if there is no such occurrence.
+ */
+ public int indexOf(String str, int fromIndex) {
+ return indexOf(value, coder(), length(), str, fromIndex);
+ }
+
+ /**
+ * Code shared by String and AbstractStringBuilder to do searches. The
+ * source is the character array being searched, and the target
+ * is the string being searched for.
+ *
+ * @param src the characters being searched.
+ * @param srcCoder the coder of the source string.
+ * @param srcCount length of the source string.
+ * @param tgtStr the characters being searched for.
+ * @param fromIndex the index to begin searching from.
+ */
+ static int indexOf(byte[] src, byte srcCoder, int srcCount,
+ String tgtStr, int fromIndex) {
+ byte[] tgt = tgtStr.value;
+ byte tgtCoder = tgtStr.coder();
+ int tgtCount = tgtStr.length();
+
+ if (fromIndex >= srcCount) {
+ return (tgtCount == 0 ? srcCount : -1);
+ }
+ if (fromIndex < 0) {
+ fromIndex = 0;
+ }
+ if (tgtCount == 0) {
+ return fromIndex;
+ }
+ if (tgtCount > srcCount) {
+ return -1;
+ }
+ if (srcCoder == tgtCoder) {
+ return srcCoder == LATIN1
+ ? StringLatin1.indexOf(src, srcCount, tgt, tgtCount, fromIndex)
+ : StringUTF16.indexOf(src, srcCount, tgt, tgtCount, fromIndex);
+ }
+ if (srcCoder == LATIN1) { // && tgtCoder == UTF16
+ return -1;
+ }
+ // srcCoder == UTF16 && tgtCoder == LATIN1) {
+ return StringUTF16.indexOfLatin1(src, srcCount, tgt, tgtCount, fromIndex);
+ }
+
+ /**
+ * Returns the index within this string of the last occurrence of the
+ * specified substring. The last occurrence of the empty string ""
+ * is considered to occur at the index value {@code this.length()}.
+ *
+ * <p>The returned index is the largest value {@code k} for which:
+ * <pre>{@code
+ * this.startsWith(str, k)
+ * }</pre>
+ * If no such value of {@code k} exists, then {@code -1} is returned.
+ *
+ * @param str the substring to search for.
+ * @return the index of the last occurrence of the specified substring,
+ * or {@code -1} if there is no such occurrence.
+ */
+ public int lastIndexOf(String str) {
+ return lastIndexOf(str, length());
+ }
+
+ /**
+ * Returns the index within this string of the last occurrence of the
+ * specified substring, searching backward starting at the specified index.
+ *
+ * <p>The returned index is the largest value {@code k} for which:
+ * <pre>{@code
+ * k <= Math.min(fromIndex, this.length()) &&
+ * this.startsWith(str, k)
+ * }</pre>
+ * If no such value of {@code k} exists, then {@code -1} is returned.
+ *
+ * @param str the substring to search for.
+ * @param fromIndex the index to start the search from.
+ * @return the index of the last occurrence of the specified substring,
+ * searching backward from the specified index,
+ * or {@code -1} if there is no such occurrence.
+ */
+ public int lastIndexOf(String str, int fromIndex) {
+ return lastIndexOf(value, coder(), length(), str, fromIndex);
+ }
+
+ /**
+ * Code shared by String and AbstractStringBuilder to do searches. The
+ * source is the character array being searched, and the target
+ * is the string being searched for.
+ *
+ * @param src the characters being searched.
+ * @param srcCoder coder handles the mapping between bytes/chars
+ * @param srcCount count of the source string.
+ * @param tgt the characters being searched for.
+ * @param fromIndex the index to begin searching from.
+ */
+ static int lastIndexOf(byte[] src, byte srcCoder, int srcCount,
+ String tgtStr, int fromIndex) {
+ byte[] tgt = tgtStr.value;
+ byte tgtCoder = tgtStr.coder();
+ int tgtCount = tgtStr.length();
+ /*
+ * Check arguments; return immediately where possible. For
+ * consistency, don't check for null str.
+ */
+ int rightIndex = srcCount - tgtCount;
+ if (fromIndex > rightIndex) {
+ fromIndex = rightIndex;
+ }
+ if (fromIndex < 0) {
+ return -1;
+ }
+ /* Empty string always matches. */
+ if (tgtCount == 0) {
+ return fromIndex;
+ }
+ if (srcCoder == tgtCoder) {
+ return srcCoder == LATIN1
+ ? StringLatin1.lastIndexOf(src, srcCount, tgt, tgtCount, fromIndex)
+ : StringUTF16.lastIndexOf(src, srcCount, tgt, tgtCount, fromIndex);
+ }
+ if (srcCoder == LATIN1) { // && tgtCoder == UTF16
+ return -1;
+ }
+ // srcCoder == UTF16 && tgtCoder == LATIN1
+ return StringUTF16.lastIndexOfLatin1(src, srcCount, tgt, tgtCount, fromIndex);
+ }
+
+ /**
+ * Returns a string that is a substring of this string. The
+ * substring begins with the character at the specified index and
+ * extends to the end of this string. <p>
+ * Examples:
+ * <blockquote><pre>
+ * "unhappy".substring(2) returns "happy"
+ * "Harbison".substring(3) returns "bison"
+ * "emptiness".substring(9) returns "" (an empty string)
+ * </pre></blockquote>
+ *
+ * @param beginIndex the beginning index, inclusive.
+ * @return the specified substring.
+ * @exception IndexOutOfBoundsException if
+ * {@code beginIndex} is negative or larger than the
+ * length of this {@code String} object.
+ */
+ public String substring(int beginIndex) {
+ if (beginIndex < 0) {
+ throw new StringIndexOutOfBoundsException(beginIndex);
+ }
+ int subLen = length() - beginIndex;
+ if (subLen < 0) {
+ throw new StringIndexOutOfBoundsException(subLen);
+ }
+ if (beginIndex == 0) {
+ return this;
+ }
+ return isLatin1() ? StringLatin1.newString(value, beginIndex, subLen)
+ : StringUTF16.newString(value, beginIndex, subLen);
+ }
+
+ /**
+ * Returns a string that is a substring of this string. The
+ * substring begins at the specified {@code beginIndex} and
+ * extends to the character at index {@code endIndex - 1}.
+ * Thus the length of the substring is {@code endIndex-beginIndex}.
+ * <p>
+ * Examples:
+ * <blockquote><pre>
+ * "hamburger".substring(4, 8) returns "urge"
+ * "smiles".substring(1, 5) returns "mile"
+ * </pre></blockquote>
+ *
+ * @param beginIndex the beginning index, inclusive.
+ * @param endIndex the ending index, exclusive.
+ * @return the specified substring.
+ * @exception IndexOutOfBoundsException if the
+ * {@code beginIndex} is negative, or
+ * {@code endIndex} is larger than the length of
+ * this {@code String} object, or
+ * {@code beginIndex} is larger than
+ * {@code endIndex}.
+ */
+ public String substring(int beginIndex, int endIndex) {
+ int length = length();
+ checkBoundsBeginEnd(beginIndex, endIndex, length);
+ int subLen = endIndex - beginIndex;
+ if (beginIndex == 0 && endIndex == length) {
+ return this;
+ }
+ return isLatin1() ? StringLatin1.newString(value, beginIndex, subLen)
+ : StringUTF16.newString(value, beginIndex, subLen);
+ }
+
+ /**
+ * Returns a character sequence that is a subsequence of this sequence.
+ *
+ * <p> An invocation of this method of the form
+ *
+ * <blockquote><pre>
+ * str.subSequence(begin, end)</pre></blockquote>
+ *
+ * behaves in exactly the same way as the invocation
+ *
+ * <blockquote><pre>
+ * str.substring(begin, end)</pre></blockquote>
+ *
+ * @apiNote
+ * This method is defined so that the {@code String} class can implement
+ * the {@link CharSequence} interface.
+ *
+ * @param beginIndex the begin index, inclusive.
+ * @param endIndex the end index, exclusive.
+ * @return the specified subsequence.
+ *
+ * @throws IndexOutOfBoundsException
+ * if {@code beginIndex} or {@code endIndex} is negative,
+ * if {@code endIndex} is greater than {@code length()},
+ * or if {@code beginIndex} is greater than {@code endIndex}
+ *
+ * @since 1.4
+ * @spec JSR-51
+ */
+ public CharSequence subSequence(int beginIndex, int endIndex) {
+ return this.substring(beginIndex, endIndex);
+ }
+
+ /**
+ * Concatenates the specified string to the end of this string.
+ * <p>
+ * If the length of the argument string is {@code 0}, then this
+ * {@code String} object is returned. Otherwise, a
+ * {@code String} object is returned that represents a character
+ * sequence that is the concatenation of the character sequence
+ * represented by this {@code String} object and the character
+ * sequence represented by the argument string.<p>
+ * Examples:
+ * <blockquote><pre>
+ * "cares".concat("s") returns "caress"
+ * "to".concat("get").concat("her") returns "together"
+ * </pre></blockquote>
+ *
+ * @param str the {@code String} that is concatenated to the end
+ * of this {@code String}.
+ * @return a string that represents the concatenation of this object's
+ * characters followed by the string argument's characters.
+ */
+ public String concat(String str) {
+ int olen = str.length();
+ if (olen == 0) {
+ return this;
+ }
+ if (coder() == str.coder()) {
+ byte[] val = this.value;
+ byte[] oval = str.value;
+ int len = val.length + oval.length;
+ byte[] buf = Arrays.copyOf(val, len);
+ System.arraycopy(oval, 0, buf, val.length, oval.length);
+ return new String(buf, coder);
+ }
+ int len = length();
+ byte[] buf = StringUTF16.newBytesFor(len + olen);
+ getBytes(buf, 0, UTF16);
+ str.getBytes(buf, len, UTF16);
+ return new String(buf, UTF16);
+ }
+
+ /**
+ * Returns a string resulting from replacing all occurrences of
+ * {@code oldChar} in this string with {@code newChar}.
+ * <p>
+ * If the character {@code oldChar} does not occur in the
+ * character sequence represented by this {@code String} object,
+ * then a reference to this {@code String} object is returned.
+ * Otherwise, a {@code String} object is returned that
+ * represents a character sequence identical to the character sequence
+ * represented by this {@code String} object, except that every
+ * occurrence of {@code oldChar} is replaced by an occurrence
+ * of {@code newChar}.
+ * <p>
+ * Examples:
+ * <blockquote><pre>
+ * "mesquite in your cellar".replace('e', 'o')
+ * returns "mosquito in your collar"
+ * "the war of baronets".replace('r', 'y')
+ * returns "the way of bayonets"
+ * "sparring with a purple porpoise".replace('p', 't')
+ * returns "starring with a turtle tortoise"
+ * "JonL".replace('q', 'x') returns "JonL" (no change)
+ * </pre></blockquote>
+ *
+ * @param oldChar the old character.
+ * @param newChar the new character.
+ * @return a string derived from this string by replacing every
+ * occurrence of {@code oldChar} with {@code newChar}.
+ */
+ public String replace(char oldChar, char newChar) {
+ if (oldChar != newChar) {
+ String ret = isLatin1() ? StringLatin1.replace(value, oldChar, newChar)
+ : StringUTF16.replace(value, oldChar, newChar);
+ if (ret != null) {
+ return ret;
+ }
+ }
+ return this;
+ }
+
+ /**
+ * Tells whether or not this string matches the given <a
+ * href="../util/regex/Pattern.html#sum">regular expression</a>.
+ *
+ * <p> An invocation of this method of the form
+ * <i>str</i>{@code .matches(}<i>regex</i>{@code )} yields exactly the
+ * same result as the expression
+ *
+ * <blockquote>
+ * {@link java.util.regex.Pattern}.{@link java.util.regex.Pattern#matches(String,CharSequence)
+ * matches(<i>regex</i>, <i>str</i>)}
+ * </blockquote>
+ *
+ * @param regex
+ * the regular expression to which this string is to be matched
+ *
+ * @return {@code true} if, and only if, this string matches the
+ * given regular expression
+ *
+ * @throws PatternSyntaxException
+ * if the regular expression's syntax is invalid
+ *
+ * @see java.util.regex.Pattern
+ *
+ * @since 1.4
+ * @spec JSR-51
+ */
+ public boolean matches(String regex) {
+ return Pattern.matches(regex, this);
+ }
+
+ /**
+ * Returns true if and only if this string contains the specified
+ * sequence of char values.
+ *
+ * @param s the sequence to search for
+ * @return true if this string contains {@code s}, false otherwise
+ * @since 1.5
+ */
+ public boolean contains(CharSequence s) {
+ return indexOf(s.toString()) >= 0;
+ }
+
+ /**
+ * Replaces the first substring of this string that matches the given <a
+ * href="../util/regex/Pattern.html#sum">regular expression</a> with the
+ * given replacement.
+ *
+ * <p> An invocation of this method of the form
+ * <i>str</i>{@code .replaceFirst(}<i>regex</i>{@code ,} <i>repl</i>{@code )}
+ * yields exactly the same result as the expression
+ *
+ * <blockquote>
+ * <code>
+ * {@link java.util.regex.Pattern}.{@link
+ * java.util.regex.Pattern#compile compile}(<i>regex</i>).{@link
+ * java.util.regex.Pattern#matcher(java.lang.CharSequence) matcher}(<i>str</i>).{@link
+ * java.util.regex.Matcher#replaceFirst replaceFirst}(<i>repl</i>)
+ * </code>
+ * </blockquote>
+ *
+ *<p>
+ * Note that backslashes ({@code \}) and dollar signs ({@code $}) in the
+ * replacement string may cause the results to be different than if it were
+ * being treated as a literal replacement string; see
+ * {@link java.util.regex.Matcher#replaceFirst}.
+ * Use {@link java.util.regex.Matcher#quoteReplacement} to suppress the special
+ * meaning of these characters, if desired.
+ *
+ * @param regex
+ * the regular expression to which this string is to be matched
+ * @param replacement
+ * the string to be substituted for the first match
+ *
+ * @return The resulting {@code String}
+ *
+ * @throws PatternSyntaxException
+ * if the regular expression's syntax is invalid
+ *
+ * @see java.util.regex.Pattern
+ *
+ * @since 1.4
+ * @spec JSR-51
+ */
+ public String replaceFirst(String regex, String replacement) {
+ return Pattern.compile(regex).matcher(this).replaceFirst(replacement);
+ }
+
+ /**
+ * Replaces each substring of this string that matches the given <a
+ * href="../util/regex/Pattern.html#sum">regular expression</a> with the
+ * given replacement.
+ *
+ * <p> An invocation of this method of the form
+ * <i>str</i>{@code .replaceAll(}<i>regex</i>{@code ,} <i>repl</i>{@code )}
+ * yields exactly the same result as the expression
+ *
+ * <blockquote>
+ * <code>
+ * {@link java.util.regex.Pattern}.{@link
+ * java.util.regex.Pattern#compile compile}(<i>regex</i>).{@link
+ * java.util.regex.Pattern#matcher(java.lang.CharSequence) matcher}(<i>str</i>).{@link
+ * java.util.regex.Matcher#replaceAll replaceAll}(<i>repl</i>)
+ * </code>
+ * </blockquote>
+ *
+ *<p>
+ * Note that backslashes ({@code \}) and dollar signs ({@code $}) in the
+ * replacement string may cause the results to be different than if it were
+ * being treated as a literal replacement string; see
+ * {@link java.util.regex.Matcher#replaceAll Matcher.replaceAll}.
+ * Use {@link java.util.regex.Matcher#quoteReplacement} to suppress the special
+ * meaning of these characters, if desired.
+ *
+ * @param regex
+ * the regular expression to which this string is to be matched
+ * @param replacement
+ * the string to be substituted for each match
+ *
+ * @return The resulting {@code String}
+ *
+ * @throws PatternSyntaxException
+ * if the regular expression's syntax is invalid
+ *
+ * @see java.util.regex.Pattern
+ *
+ * @since 1.4
+ * @spec JSR-51
+ */
+ public String replaceAll(String regex, String replacement) {
+ return Pattern.compile(regex).matcher(this).replaceAll(replacement);
+ }
+
+ /**
+ * Replaces each substring of this string that matches the literal target
+ * sequence with the specified literal replacement sequence. The
+ * replacement proceeds from the beginning of the string to the end, for
+ * example, replacing "aa" with "b" in the string "aaa" will result in
+ * "ba" rather than "ab".
+ *
+ * @param target The sequence of char values to be replaced
+ * @param replacement The replacement sequence of char values
+ * @return The resulting string
+ * @since 1.5
+ */
+ public String replace(CharSequence target, CharSequence replacement) {
+ String tgtStr = target.toString();
+ String replStr = replacement.toString();
+ int j = indexOf(tgtStr);
+ if (j < 0) {
+ return this;
+ }
+ int tgtLen = tgtStr.length();
+ int tgtLen1 = Math.max(tgtLen, 1);
+ int thisLen = length();
+
+ int newLenHint = thisLen - tgtLen + replStr.length();
+ if (newLenHint < 0) {
+ throw new OutOfMemoryError();
+ }
+ StringBuilder sb = new StringBuilder(newLenHint);
+ int i = 0;
+ do {
+ sb.append(this, i, j).append(replStr);
+ i = j + tgtLen;
+ } while (j < thisLen && (j = indexOf(tgtStr, j + tgtLen1)) > 0);
+ return sb.append(this, i, thisLen).toString();
+ }
+
+ /**
+ * Splits this string around matches of the given
+ * <a href="../util/regex/Pattern.html#sum">regular expression</a>.
+ *
+ * <p> The array returned by this method contains each substring of this
+ * string that is terminated by another substring that matches the given
+ * expression or is terminated by the end of the string. The substrings in
+ * the array are in the order in which they occur in this string. If the
+ * expression does not match any part of the input then the resulting array
+ * has just one element, namely this string.
+ *
+ * <p> When there is a positive-width match at the beginning of this
+ * string then an empty leading substring is included at the beginning
+ * of the resulting array. A zero-width match at the beginning however
+ * never produces such empty leading substring.
+ *
+ * <p> The {@code limit} parameter controls the number of times the
+ * pattern is applied and therefore affects the length of the resulting
+ * array. If the limit <i>n</i> is greater than zero then the pattern
+ * will be applied at most <i>n</i> - 1 times, the array's
+ * length will be no greater than <i>n</i>, and the array's last entry
+ * will contain all input beyond the last matched delimiter. If <i>n</i>
+ * is non-positive then the pattern will be applied as many times as
+ * possible and the array can have any length. If <i>n</i> is zero then
+ * the pattern will be applied as many times as possible, the array can
+ * have any length, and trailing empty strings will be discarded.
+ *
+ * <p> The string {@code "boo:and:foo"}, for example, yields the
+ * following results with these parameters:
+ *
+ * <blockquote><table class="plain">
+ * <caption style="display:none">Split example showing regex, limit, and result</caption>
+ * <thead>
+ * <tr>
+ * <th scope="col">Regex</th>
+ * <th scope="col">Limit</th>
+ * <th scope="col">Result</th>
+ * </tr>
+ * </thead>
+ * <tbody>
+ * <tr><th scope="row" rowspan="3" style="font-weight:normal">:</th>
+ * <th scope="row" style="font-weight:normal; text-align:right; padding-right:1em">2</th>
+ * <td>{@code { "boo", "and:foo" }}</td></tr>
+ * <tr><!-- : -->
+ * <th scope="row" style="font-weight:normal; text-align:right; padding-right:1em">5</th>
+ * <td>{@code { "boo", "and", "foo" }}</td></tr>
+ * <tr><!-- : -->
+ * <th scope="row" style="font-weight:normal; text-align:right; padding-right:1em">-2</th>
+ * <td>{@code { "boo", "and", "foo" }}</td></tr>
+ * <tr><th scope="row" rowspan="3" style="font-weight:normal">o</th>
+ * <th scope="row" style="font-weight:normal; text-align:right; padding-right:1em">5</th>
+ * <td>{@code { "b", "", ":and:f", "", "" }}</td></tr>
+ * <tr><!-- o -->
+ * <th scope="row" style="font-weight:normal; text-align:right; padding-right:1em">-2</th>
+ * <td>{@code { "b", "", ":and:f", "", "" }}</td></tr>
+ * <tr><!-- o -->
+ * <th scope="row" style="font-weight:normal; text-align:right; padding-right:1em">0</th>
+ * <td>{@code { "b", "", ":and:f" }}</td></tr>
+ * </tbody>
+ * </table></blockquote>
+ *
+ * <p> An invocation of this method of the form
+ * <i>str.</i>{@code split(}<i>regex</i>{@code ,} <i>n</i>{@code )}
+ * yields the same result as the expression
+ *
+ * <blockquote>
+ * <code>
+ * {@link java.util.regex.Pattern}.{@link
+ * java.util.regex.Pattern#compile compile}(<i>regex</i>).{@link
+ * java.util.regex.Pattern#split(java.lang.CharSequence,int) split}(<i>str</i>, <i>n</i>)
+ * </code>
+ * </blockquote>
+ *
+ *
+ * @param regex
+ * the delimiting regular expression
+ *
+ * @param limit
+ * the result threshold, as described above
+ *
+ * @return the array of strings computed by splitting this string
+ * around matches of the given regular expression
+ *
+ * @throws PatternSyntaxException
+ * if the regular expression's syntax is invalid
+ *
+ * @see java.util.regex.Pattern
+ *
+ * @since 1.4
+ * @spec JSR-51
+ */
+ public String[] split(String regex, int limit) {
+ /* fastpath if the regex is a
+ (1)one-char String and this character is not one of the
+ RegEx's meta characters ".$|()[{^?*+\\", or
+ (2)two-char String and the first char is the backslash and
+ the second is not the ascii digit or ascii letter.
+ */
+ char ch = 0;
+ if (((regex.length() == 1 &&
+ ".$|()[{^?*+\\".indexOf(ch = regex.charAt(0)) == -1) ||
+ (regex.length() == 2 &&
+ regex.charAt(0) == '\\' &&
+ (((ch = regex.charAt(1))-'0')|('9'-ch)) < 0 &&
+ ((ch-'a')|('z'-ch)) < 0 &&
+ ((ch-'A')|('Z'-ch)) < 0)) &&
+ (ch < Character.MIN_HIGH_SURROGATE ||
+ ch > Character.MAX_LOW_SURROGATE))
+ {
+ int off = 0;
+ int next = 0;
+ boolean limited = limit > 0;
+ ArrayList<String> list = new ArrayList<>();
+ while ((next = indexOf(ch, off)) != -1) {
+ if (!limited || list.size() < limit - 1) {
+ list.add(substring(off, next));
+ off = next + 1;
+ } else { // last one
+ //assert (list.size() == limit - 1);
+ int last = length();
+ list.add(substring(off, last));
+ off = last;
+ break;
+ }
+ }
+ // If no match was found, return this
+ if (off == 0)
+ return new String[]{this};
+
+ // Add remaining segment
+ if (!limited || list.size() < limit)
+ list.add(substring(off, length()));
+
+ // Construct result
+ int resultSize = list.size();
+ if (limit == 0) {
+ while (resultSize > 0 && list.get(resultSize - 1).length() == 0) {
+ resultSize--;
+ }
+ }
+ String[] result = new String[resultSize];
+ return list.subList(0, resultSize).toArray(result);
+ }
+ return Pattern.compile(regex).split(this, limit);
+ }
+
+ /**
+ * Splits this string around matches of the given <a
+ * href="../util/regex/Pattern.html#sum">regular expression</a>.
+ *
+ * <p> This method works as if by invoking the two-argument {@link
+ * #split(String, int) split} method with the given expression and a limit
+ * argument of zero. Trailing empty strings are therefore not included in
+ * the resulting array.
+ *
+ * <p> The string {@code "boo:and:foo"}, for example, yields the following
+ * results with these expressions:
+ *
+ * <blockquote><table class="plain">
+ * <caption style="display:none">Split examples showing regex and result</caption>
+ * <thead>
+ * <tr>
+ * <th scope="col">Regex</th>
+ * <th scope="col">Result</th>
+ * </tr>
+ * </thead>
+ * <tbody>
+ * <tr><th scope="row" style="text-weight:normal">:</th>
+ * <td>{@code { "boo", "and", "foo" }}</td></tr>
+ * <tr><th scope="row" style="text-weight:normal">o</th>
+ * <td>{@code { "b", "", ":and:f" }}</td></tr>
+ * </tbody>
+ * </table></blockquote>
+ *
+ *
+ * @param regex
+ * the delimiting regular expression
+ *
+ * @return the array of strings computed by splitting this string
+ * around matches of the given regular expression
+ *
+ * @throws PatternSyntaxException
+ * if the regular expression's syntax is invalid
+ *
+ * @see java.util.regex.Pattern
+ *
+ * @since 1.4
+ * @spec JSR-51
+ */
+ public String[] split(String regex) {
+ return split(regex, 0);
+ }
+
+ /**
+ * Returns a new String composed of copies of the
+ * {@code CharSequence elements} joined together with a copy of
+ * the specified {@code delimiter}.
+ *
+ * <blockquote>For example,
+ * <pre>{@code
+ * String message = String.join("-", "Java", "is", "cool");
+ * // message returned is: "Java-is-cool"
+ * }</pre></blockquote>
+ *
+ * Note that if an element is null, then {@code "null"} is added.
+ *
+ * @param delimiter the delimiter that separates each element
+ * @param elements the elements to join together.
+ *
+ * @return a new {@code String} that is composed of the {@code elements}
+ * separated by the {@code delimiter}
+ *
+ * @throws NullPointerException If {@code delimiter} or {@code elements}
+ * is {@code null}
+ *
+ * @see java.util.StringJoiner
+ * @since 1.8
+ */
+ public static String join(CharSequence delimiter, CharSequence... elements) {
+ Objects.requireNonNull(delimiter);
+ Objects.requireNonNull(elements);
+ // Number of elements not likely worth Arrays.stream overhead.
+ StringJoiner joiner = new StringJoiner(delimiter);
+ for (CharSequence cs: elements) {
+ joiner.add(cs);
+ }
+ return joiner.toString();
+ }
+
+ /**
+ * Returns a new {@code String} composed of copies of the
+ * {@code CharSequence elements} joined together with a copy of the
+ * specified {@code delimiter}.
+ *
+ * <blockquote>For example,
+ * <pre>{@code
+ * List<String> strings = List.of("Java", "is", "cool");
+ * String message = String.join(" ", strings);
+ * //message returned is: "Java is cool"
+ *
+ * Set<String> strings =
+ * new LinkedHashSet<>(List.of("Java", "is", "very", "cool"));
+ * String message = String.join("-", strings);
+ * //message returned is: "Java-is-very-cool"
+ * }</pre></blockquote>
+ *
+ * Note that if an individual element is {@code null}, then {@code "null"} is added.
+ *
+ * @param delimiter a sequence of characters that is used to separate each
+ * of the {@code elements} in the resulting {@code String}
+ * @param elements an {@code Iterable} that will have its {@code elements}
+ * joined together.
+ *
+ * @return a new {@code String} that is composed from the {@code elements}
+ * argument
+ *
+ * @throws NullPointerException If {@code delimiter} or {@code elements}
+ * is {@code null}
+ *
+ * @see #join(CharSequence,CharSequence...)
+ * @see java.util.StringJoiner
+ * @since 1.8
+ */
+ public static String join(CharSequence delimiter,
+ Iterable<? extends CharSequence> elements) {
+ Objects.requireNonNull(delimiter);
+ Objects.requireNonNull(elements);
+ StringJoiner joiner = new StringJoiner(delimiter);
+ for (CharSequence cs: elements) {
+ joiner.add(cs);
+ }
+ return joiner.toString();
+ }
+
+ /**
+ * Converts all of the characters in this {@code String} to lower
+ * case using the rules of the given {@code Locale}. Case mapping is based
+ * on the Unicode Standard version specified by the {@link java.lang.Character Character}
+ * class. Since case mappings are not always 1:1 char mappings, the resulting
+ * {@code String} may be a different length than the original {@code String}.
+ * <p>
+ * Examples of lowercase mappings are in the following table:
+ * <table class="plain">
+ * <caption style="display:none">Lowercase mapping examples showing language code of locale, upper case, lower case, and description</caption>
+ * <thead>
+ * <tr>
+ * <th scope="col">Language Code of Locale</th>
+ * <th scope="col">Upper Case</th>
+ * <th scope="col">Lower Case</th>
+ * <th scope="col">Description</th>
+ * </tr>
+ * </thead>
+ * <tbody>
+ * <tr>
+ * <td>tr (Turkish)</td>
+ * <th scope="row" style="font-weight:normal; text-align:left">\u0130</th>
+ * <td>\u0069</td>
+ * <td>capital letter I with dot above -> small letter i</td>
+ * </tr>
+ * <tr>
+ * <td>tr (Turkish)</td>
+ * <th scope="row" style="font-weight:normal; text-align:left">\u0049</th>
+ * <td>\u0131</td>
+ * <td>capital letter I -> small letter dotless i </td>
+ * </tr>
+ * <tr>
+ * <td>(all)</td>
+ * <th scope="row" style="font-weight:normal; text-align:left">French Fries</th>
+ * <td>french fries</td>
+ * <td>lowercased all chars in String</td>
+ * </tr>
+ * <tr>
+ * <td>(all)</td>
+ * <th scope="row" style="font-weight:normal; text-align:left">
+ * ΙΧΘΥΣ</th>
+ * <td>ιχθυσ</td>
+ * <td>lowercased all chars in String</td>
+ * </tr>
+ * </tbody>
+ * </table>
+ *
+ * @param locale use the case transformation rules for this locale
+ * @return the {@code String}, converted to lowercase.
+ * @see java.lang.String#toLowerCase()
+ * @see java.lang.String#toUpperCase()
+ * @see java.lang.String#toUpperCase(Locale)
+ * @since 1.1
+ */
+ public String toLowerCase(Locale locale) {
+ return isLatin1() ? StringLatin1.toLowerCase(this, value, locale)
+ : StringUTF16.toLowerCase(this, value, locale);
+ }
+
+ /**
+ * Converts all of the characters in this {@code String} to lower
+ * case using the rules of the default locale. This is equivalent to calling
+ * {@code toLowerCase(Locale.getDefault())}.
+ * <p>
+ * <b>Note:</b> This method is locale sensitive, and may produce unexpected
+ * results if used for strings that are intended to be interpreted locale
+ * independently.
+ * Examples are programming language identifiers, protocol keys, and HTML
+ * tags.
+ * For instance, {@code "TITLE".toLowerCase()} in a Turkish locale
+ * returns {@code "t\u005Cu0131tle"}, where '\u005Cu0131' is the
+ * LATIN SMALL LETTER DOTLESS I character.
+ * To obtain correct results for locale insensitive strings, use
+ * {@code toLowerCase(Locale.ROOT)}.
+ *
+ * @return the {@code String}, converted to lowercase.
+ * @see java.lang.String#toLowerCase(Locale)
+ */
+ public String toLowerCase() {
+ return toLowerCase(Locale.getDefault());
+ }
+
+ /**
+ * Converts all of the characters in this {@code String} to upper
+ * case using the rules of the given {@code Locale}. Case mapping is based
+ * on the Unicode Standard version specified by the {@link java.lang.Character Character}
+ * class. Since case mappings are not always 1:1 char mappings, the resulting
+ * {@code String} may be a different length than the original {@code String}.
+ * <p>
+ * Examples of locale-sensitive and 1:M case mappings are in the following table.
+ *
+ * <table class="plain">
+ * <caption style="display:none">Examples of locale-sensitive and 1:M case mappings. Shows Language code of locale, lower case, upper case, and description.</caption>
+ * <thead>
+ * <tr>
+ * <th scope="col">Language Code of Locale</th>
+ * <th scope="col">Lower Case</th>
+ * <th scope="col">Upper Case</th>
+ * <th scope="col">Description</th>
+ * </tr>
+ * </thead>
+ * <tbody>
+ * <tr>
+ * <td>tr (Turkish)</td>
+ * <th scope="row" style="font-weight:normal; text-align:left">\u0069</th>
+ * <td>\u0130</td>
+ * <td>small letter i -> capital letter I with dot above</td>
+ * </tr>
+ * <tr>
+ * <td>tr (Turkish)</td>
+ * <th scope="row" style="font-weight:normal; text-align:left">\u0131</th>
+ * <td>\u0049</td>
+ * <td>small letter dotless i -> capital letter I</td>
+ * </tr>
+ * <tr>
+ * <td>(all)</td>
+ * <th scope="row" style="font-weight:normal; text-align:left">\u00df</th>
+ * <td>\u0053 \u0053</td>
+ * <td>small letter sharp s -> two letters: SS</td>
+ * </tr>
+ * <tr>
+ * <td>(all)</td>
+ * <th scope="row" style="font-weight:normal; text-align:left">Fahrvergnügen</th>
+ * <td>FAHRVERGNÜGEN</td>
+ * <td></td>
+ * </tr>
+ * </tbody>
+ * </table>
+ * @param locale use the case transformation rules for this locale
+ * @return the {@code String}, converted to uppercase.
+ * @see java.lang.String#toUpperCase()
+ * @see java.lang.String#toLowerCase()
+ * @see java.lang.String#toLowerCase(Locale)
+ * @since 1.1
+ */
+ public String toUpperCase(Locale locale) {
+ return isLatin1() ? StringLatin1.toUpperCase(this, value, locale)
+ : StringUTF16.toUpperCase(this, value, locale);
+ }
+
+ /**
+ * Converts all of the characters in this {@code String} to upper
+ * case using the rules of the default locale. This method is equivalent to
+ * {@code toUpperCase(Locale.getDefault())}.
+ * <p>
+ * <b>Note:</b> This method is locale sensitive, and may produce unexpected
+ * results if used for strings that are intended to be interpreted locale
+ * independently.
+ * Examples are programming language identifiers, protocol keys, and HTML
+ * tags.
+ * For instance, {@code "title".toUpperCase()} in a Turkish locale
+ * returns {@code "T\u005Cu0130TLE"}, where '\u005Cu0130' is the
+ * LATIN CAPITAL LETTER I WITH DOT ABOVE character.
+ * To obtain correct results for locale insensitive strings, use
+ * {@code toUpperCase(Locale.ROOT)}.
+ *
+ * @return the {@code String}, converted to uppercase.
+ * @see java.lang.String#toUpperCase(Locale)
+ */
+ public String toUpperCase() {
+ return toUpperCase(Locale.getDefault());
+ }
+
+ /**
+ * Returns a string whose value is this string, with any leading and trailing
+ * whitespace removed.
+ * <p>
+ * If this {@code String} object represents an empty character
+ * sequence, or the first and last characters of character sequence
+ * represented by this {@code String} object both have codes
+ * greater than {@code '\u005Cu0020'} (the space character), then a
+ * reference to this {@code String} object is returned.
+ * <p>
+ * Otherwise, if there is no character with a code greater than
+ * {@code '\u005Cu0020'} in the string, then a
+ * {@code String} object representing an empty string is
+ * returned.
+ * <p>
+ * Otherwise, let <i>k</i> be the index of the first character in the
+ * string whose code is greater than {@code '\u005Cu0020'}, and let
+ * <i>m</i> be the index of the last character in the string whose code
+ * is greater than {@code '\u005Cu0020'}. A {@code String}
+ * object is returned, representing the substring of this string that
+ * begins with the character at index <i>k</i> and ends with the
+ * character at index <i>m</i>-that is, the result of
+ * {@code this.substring(k, m + 1)}.
+ * <p>
+ * This method may be used to trim whitespace (as defined above) from
+ * the beginning and end of a string.
+ *
+ * @return A string whose value is this string, with any leading and trailing white
+ * space removed, or this string if it has no leading or
+ * trailing white space.
+ */
+ public String trim() {
+ String ret = isLatin1() ? StringLatin1.trim(value)
+ : StringUTF16.trim(value);
+ return ret == null ? this : ret;
+ }
+
+ /**
+ * This object (which is already a string!) is itself returned.
+ *
+ * @return the string itself.
+ */
+ public String toString() {
+ return this;
+ }
+
+ /**
+ * Returns a stream of {@code int} zero-extending the {@code char} values
+ * from this sequence. Any char which maps to a <a
+ * href="{@docRoot}/java/lang/Character.html#unicode">surrogate code
+ * point</a> is passed through uninterpreted.
+ *
+ * @return an IntStream of char values from this sequence
+ */
+ @Override
+ public IntStream chars() {
+ return StreamSupport.intStream(
+ isLatin1() ? new StringLatin1.CharsSpliterator(value, Spliterator.IMMUTABLE)
+ : new StringUTF16.CharsSpliterator(value, Spliterator.IMMUTABLE),
+ false);
+ }
+
+
+ /**
+ * Returns a stream of code point values from this sequence. Any surrogate
+ * pairs encountered in the sequence are combined as if by {@linkplain
+ * Character#toCodePoint Character.toCodePoint} and the result is passed
+ * to the stream. Any other code units, including ordinary BMP characters,
+ * unpaired surrogates, and undefined code units, are zero-extended to
+ * {@code int} values which are then passed to the stream.
+ *
+ * @return an IntStream of Unicode code points from this sequence
+ */
+ @Override
+ public IntStream codePoints() {
+ return StreamSupport.intStream(
+ isLatin1() ? new StringLatin1.CharsSpliterator(value, Spliterator.IMMUTABLE)
+ : new StringUTF16.CodePointsSpliterator(value, Spliterator.IMMUTABLE),
+ false);
+ }
+
+ /**
+ * Converts this string to a new character array.
+ *
+ * @return a newly allocated character array whose length is the length
+ * of this string and whose contents are initialized to contain
+ * the character sequence represented by this string.
+ */
+ public char[] toCharArray() {
+ return isLatin1() ? StringLatin1.toChars(value)
+ : StringUTF16.toChars(value);
+ }
+
+ /**
+ * Returns a formatted string using the specified format string and
+ * arguments.
+ *
+ * <p> The locale always used is the one returned by {@link
+ * java.util.Locale#getDefault(java.util.Locale.Category)
+ * Locale.getDefault(Locale.Category)} with
+ * {@link java.util.Locale.Category#FORMAT FORMAT} category specified.
+ *
+ * @param format
+ * A <a href="../util/Formatter.html#syntax">format string</a>
+ *
+ * @param args
+ * Arguments referenced by the format specifiers in the format
+ * string. If there are more arguments than format specifiers, the
+ * extra arguments are ignored. The number of arguments is
+ * variable and may be zero. The maximum number of arguments is
+ * limited by the maximum dimension of a Java array as defined by
+ * <cite>The Java™ Virtual Machine Specification</cite>.
+ * The behaviour on a
+ * {@code null} argument depends on the <a
+ * href="../util/Formatter.html#syntax">conversion</a>.
+ *
+ * @throws java.util.IllegalFormatException
+ * If a format string contains an illegal syntax, a format
+ * specifier that is incompatible with the given arguments,
+ * insufficient arguments given the format string, or other
+ * illegal conditions. For specification of all possible
+ * formatting errors, see the <a
+ * href="../util/Formatter.html#detail">Details</a> section of the
+ * formatter class specification.
+ *
+ * @return A formatted string
+ *
+ * @see java.util.Formatter
+ * @since 1.5
+ */
+ public static String format(String format, Object... args) {
+ return new Formatter().format(format, args).toString();
+ }
+
+ /**
+ * Returns a formatted string using the specified locale, format string,
+ * and arguments.
+ *
+ * @param l
+ * The {@linkplain java.util.Locale locale} to apply during
+ * formatting. If {@code l} is {@code null} then no localization
+ * is applied.
+ *
+ * @param format
+ * A <a href="../util/Formatter.html#syntax">format string</a>
+ *
+ * @param args
+ * Arguments referenced by the format specifiers in the format
+ * string. If there are more arguments than format specifiers, the
+ * extra arguments are ignored. The number of arguments is
+ * variable and may be zero. The maximum number of arguments is
+ * limited by the maximum dimension of a Java array as defined by
+ * <cite>The Java™ Virtual Machine Specification</cite>.
+ * The behaviour on a
+ * {@code null} argument depends on the
+ * <a href="../util/Formatter.html#syntax">conversion</a>.
+ *
+ * @throws java.util.IllegalFormatException
+ * If a format string contains an illegal syntax, a format
+ * specifier that is incompatible with the given arguments,
+ * insufficient arguments given the format string, or other
+ * illegal conditions. For specification of all possible
+ * formatting errors, see the <a
+ * href="../util/Formatter.html#detail">Details</a> section of the
+ * formatter class specification
+ *
+ * @return A formatted string
+ *
+ * @see java.util.Formatter
+ * @since 1.5
+ */
+ public static String format(Locale l, String format, Object... args) {
+ return new Formatter(l).format(format, args).toString();
+ }
+
+ /**
+ * Returns the string representation of the {@code Object} argument.
+ *
+ * @param obj an {@code Object}.
+ * @return if the argument is {@code null}, then a string equal to
+ * {@code "null"}; otherwise, the value of
+ * {@code obj.toString()} is returned.
+ * @see java.lang.Object#toString()
+ */
+ public static String valueOf(Object obj) {
+ return (obj == null) ? "null" : obj.toString();
+ }
+
+ /**
+ * Returns the string representation of the {@code char} array
+ * argument. The contents of the character array are copied; subsequent
+ * modification of the character array does not affect the returned
+ * string.
+ *
+ * @param data the character array.
+ * @return a {@code String} that contains the characters of the
+ * character array.
+ */
+ public static String valueOf(char data[]) {
+ return new String(data);
+ }
+
+ /**
+ * Returns the string representation of a specific subarray of the
+ * {@code char} array argument.
+ * <p>
+ * The {@code offset} argument is the index of the first
+ * character of the subarray. The {@code count} argument
+ * specifies the length of the subarray. The contents of the subarray
+ * are copied; subsequent modification of the character array does not
+ * affect the returned string.
+ *
+ * @param data the character array.
+ * @param offset initial offset of the subarray.
+ * @param count length of the subarray.
+ * @return a {@code String} that contains the characters of the
+ * specified subarray of the character array.
+ * @exception IndexOutOfBoundsException if {@code offset} is
+ * negative, or {@code count} is negative, or
+ * {@code offset+count} is larger than
+ * {@code data.length}.
+ */
+ public static String valueOf(char data[], int offset, int count) {
+ return new String(data, offset, count);
+ }
+
+ /**
+ * Equivalent to {@link #valueOf(char[], int, int)}.
+ *
+ * @param data the character array.
+ * @param offset initial offset of the subarray.
+ * @param count length of the subarray.
+ * @return a {@code String} that contains the characters of the
+ * specified subarray of the character array.
+ * @exception IndexOutOfBoundsException if {@code offset} is
+ * negative, or {@code count} is negative, or
+ * {@code offset+count} is larger than
+ * {@code data.length}.
+ */
+ public static String copyValueOf(char data[], int offset, int count) {
+ return new String(data, offset, count);
+ }
+
+ /**
+ * Equivalent to {@link #valueOf(char[])}.
+ *
+ * @param data the character array.
+ * @return a {@code String} that contains the characters of the
+ * character array.
+ */
+ public static String copyValueOf(char data[]) {
+ return new String(data);
+ }
+
+ /**
+ * Returns the string representation of the {@code boolean} argument.
+ *
+ * @param b a {@code boolean}.
+ * @return if the argument is {@code true}, a string equal to
+ * {@code "true"} is returned; otherwise, a string equal to
+ * {@code "false"} is returned.
+ */
+ public static String valueOf(boolean b) {
+ return b ? "true" : "false";
+ }
+
+ /**
+ * Returns the string representation of the {@code char}
+ * argument.
+ *
+ * @param c a {@code char}.
+ * @return a string of length {@code 1} containing
+ * as its single character the argument {@code c}.
+ */
+ public static String valueOf(char c) {
+ if (COMPACT_STRINGS && StringLatin1.canEncode(c)) {
+ return new String(StringLatin1.toBytes(c), LATIN1);
+ }
+ return new String(StringUTF16.toBytes(c), UTF16);
+ }
+
+ /**
+ * Returns the string representation of the {@code int} argument.
+ * <p>
+ * The representation is exactly the one returned by the
+ * {@code Integer.toString} method of one argument.
+ *
+ * @param i an {@code int}.
+ * @return a string representation of the {@code int} argument.
+ * @see java.lang.Integer#toString(int, int)
+ */
+ public static String valueOf(int i) {
+ return Integer.toString(i);
+ }
+
+ /**
+ * Returns the string representation of the {@code long} argument.
+ * <p>
+ * The representation is exactly the one returned by the
+ * {@code Long.toString} method of one argument.
+ *
+ * @param l a {@code long}.
+ * @return a string representation of the {@code long} argument.
+ * @see java.lang.Long#toString(long)
+ */
+ public static String valueOf(long l) {
+ return Long.toString(l);
+ }
+
+ /**
+ * Returns the string representation of the {@code float} argument.
+ * <p>
+ * The representation is exactly the one returned by the
+ * {@code Float.toString} method of one argument.
+ *
+ * @param f a {@code float}.
+ * @return a string representation of the {@code float} argument.
+ * @see java.lang.Float#toString(float)
+ */
+ public static String valueOf(float f) {
+ return Float.toString(f);
+ }
+
+ /**
+ * Returns the string representation of the {@code double} argument.
+ * <p>
+ * The representation is exactly the one returned by the
+ * {@code Double.toString} method of one argument.
+ *
+ * @param d a {@code double}.
+ * @return a string representation of the {@code double} argument.
+ * @see java.lang.Double#toString(double)
+ */
+ public static String valueOf(double d) {
+ return Double.toString(d);
+ }
+
+ /**
+ * Returns a canonical representation for the string object.
+ * <p>
+ * A pool of strings, initially empty, is maintained privately by the
+ * class {@code String}.
+ * <p>
+ * When the intern method is invoked, if the pool already contains a
+ * string equal to this {@code String} object as determined by
+ * the {@link #equals(Object)} method, then the string from the pool is
+ * returned. Otherwise, this {@code String} object is added to the
+ * pool and a reference to this {@code String} object is returned.
+ * <p>
+ * It follows that for any two strings {@code s} and {@code t},
+ * {@code s.intern() == t.intern()} is {@code true}
+ * if and only if {@code s.equals(t)} is {@code true}.
+ * <p>
+ * All literal strings and string-valued constant expressions are
+ * interned. String literals are defined in section 3.10.5 of the
+ * <cite>The Java™ Language Specification</cite>.
+ *
+ * @return a string that has the same contents as this string, but is
+ * guaranteed to be from a pool of unique strings.
+ * @jls 3.10.5 String Literals
+ */
+ public native String intern();
+
+ ////////////////////////////////////////////////////////////////
+
+ /**
+ * Copy character bytes from this string into dst starting at dstBegin.
+ * This method doesn't perform any range checking.
+ *
+ * Invoker guarantees: dst is in UTF16 (inflate itself for asb), if two
+ * coders are different, and dst is big enough (range check)
+ *
+ * @param dstBegin the char index, not offset of byte[]
+ * @param coder the coder of dst[]
+ */
+ void getBytes(byte dst[], int dstBegin, byte coder) {
+ if (coder() == coder) {
+ System.arraycopy(value, 0, dst, dstBegin << coder, value.length);
+ } else { // this.coder == LATIN && coder == UTF16
+ StringLatin1.inflate(value, 0, dst, dstBegin, value.length);
+ }
+ }
+
+ /*
+ * Package private constructor. Trailing Void argument is there for
+ * disambiguating it against other (public) constructors.
+ *
+ * Stores the char[] value into a byte[] that each byte represents
+ * the8 low-order bits of the corresponding character, if the char[]
+ * contains only latin1 character. Or a byte[] that stores all
+ * characters in their byte sequences defined by the {@code StringUTF16}.
+ */
+ String(char[] value, int off, int len, Void sig) {
+ if (len == 0) {
+ this.value = "".value;
+ this.coder = "".coder;
+ return;
+ }
+ if (COMPACT_STRINGS) {
+ byte[] val = StringUTF16.compress(value, off, len);
+ if (val != null) {
+ this.value = val;
+ this.coder = LATIN1;
+ return;
+ }
+ }
+ this.coder = UTF16;
+ this.value = StringUTF16.toBytes(value, off, len);
+ }
+
+ /*
+ * Package private constructor. Trailing Void argument is there for
+ * disambiguating it against other (public) constructors.
+ */
+ String(AbstractStringBuilder asb, Void sig) {
+ byte[] val = asb.getValue();
+ int length = asb.length();
+ if (asb.isLatin1()) {
+ this.coder = LATIN1;
+ this.value = Arrays.copyOfRange(val, 0, length);
+ } else {
+ if (COMPACT_STRINGS) {
+ byte[] buf = StringUTF16.compress(val, 0, length);
+ if (buf != null) {
+ this.coder = LATIN1;
+ this.value = buf;
+ return;
+ }
+ }
+ this.coder = UTF16;
+ this.value = Arrays.copyOfRange(val, 0, length << 1);
+ }
+ }
+
+ /*
+ * Package private constructor which shares value array for speed.
+ */
+ String(byte[] value, byte coder) {
+ this.value = value;
+ this.coder = coder;
+ }
+
+ byte coder() {
+ return COMPACT_STRINGS ? coder : UTF16;
+ }
+
+ private boolean isLatin1() {
+ return COMPACT_STRINGS && coder == LATIN1;
+ }
+
+ @Native static final byte LATIN1 = 0;
+ @Native static final byte UTF16 = 1;
+
+ /*
+ * StringIndexOutOfBoundsException if {@code index} is
+ * negative or greater than or equal to {@code length}.
+ */
+ static void checkIndex(int index, int length) {
+ if (index < 0 || index >= length) {
+ throw new StringIndexOutOfBoundsException("index " + index +
+ ",length " + length);
+ }
+ }
+
+ /*
+ * StringIndexOutOfBoundsException if {@code offset}
+ * is negative or greater than {@code length}.
+ */
+ static void checkOffset(int offset, int length) {
+ if (offset < 0 || offset > length) {
+ throw new StringIndexOutOfBoundsException("offset " + offset +
+ ",length " + length);
+ }
+ }
+
+ /*
+ * Check {@code offset}, {@code count} against {@code 0} and {@code length}
+ * bounds.
+ *
+ * @throws StringIndexOutOfBoundsException
+ * If {@code offset} is negative, {@code count} is negative,
+ * or {@code offset} is greater than {@code length - count}
+ */
+ static void checkBoundsOffCount(int offset, int count, int length) {
+ if (offset < 0 || count < 0 || offset > length - count) {
+ throw new StringIndexOutOfBoundsException(
+ "offset " + offset + ", count " + count + ", length " + length);
+ }
+ }
+
+ /*
+ * Check {@code begin}, {@code end} against {@code 0} and {@code length}
+ * bounds.
+ *
+ * @throws StringIndexOutOfBoundsException
+ * If {@code begin} is negative, {@code begin} is greater than
+ * {@code end}, or {@code end} is greater than {@code length}.
+ */
+ static void checkBoundsBeginEnd(int begin, int end, int length) {
+ if (begin < 0 || begin > end || end > length) {
+ throw new StringIndexOutOfBoundsException(
+ "begin " + begin + ", end " + end + ", length " + length);
+ }
+ }
+}