--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/java/io/CharArrayReader.java Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,232 @@
+/*
+ * Copyright 1996-2005 Sun Microsystems, Inc. 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. Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package java.io;
+
+/**
+ * This class implements a character buffer that can be used as a
+ * character-input stream.
+ *
+ * @author Herb Jellinek
+ * @since JDK1.1
+ */
+public class CharArrayReader extends Reader {
+ /** The character buffer. */
+ protected char buf[];
+
+ /** The current buffer position. */
+ protected int pos;
+
+ /** The position of mark in buffer. */
+ protected int markedPos = 0;
+
+ /**
+ * The index of the end of this buffer. There is not valid
+ * data at or beyond this index.
+ */
+ protected int count;
+
+ /**
+ * Creates a CharArrayReader from the specified array of chars.
+ * @param buf Input buffer (not copied)
+ */
+ public CharArrayReader(char buf[]) {
+ this.buf = buf;
+ this.pos = 0;
+ this.count = buf.length;
+ }
+
+ /**
+ * Creates a CharArrayReader from the specified array of chars.
+ *
+ * <p> The resulting reader will start reading at the given
+ * <tt>offset</tt>. The total number of <tt>char</tt> values that can be
+ * read from this reader will be either <tt>length</tt> or
+ * <tt>buf.length-offset</tt>, whichever is smaller.
+ *
+ * @throws IllegalArgumentException
+ * If <tt>offset</tt> is negative or greater than
+ * <tt>buf.length</tt>, or if <tt>length</tt> is negative, or if
+ * the sum of these two values is negative.
+ *
+ * @param buf Input buffer (not copied)
+ * @param offset Offset of the first char to read
+ * @param length Number of chars to read
+ */
+ public CharArrayReader(char buf[], int offset, int length) {
+ if ((offset < 0) || (offset > buf.length) || (length < 0) ||
+ ((offset + length) < 0)) {
+ throw new IllegalArgumentException();
+ }
+ this.buf = buf;
+ this.pos = offset;
+ this.count = Math.min(offset + length, buf.length);
+ this.markedPos = offset;
+ }
+
+ /** Checks to make sure that the stream has not been closed */
+ private void ensureOpen() throws IOException {
+ if (buf == null)
+ throw new IOException("Stream closed");
+ }
+
+ /**
+ * Reads a single character.
+ *
+ * @exception IOException If an I/O error occurs
+ */
+ public int read() throws IOException {
+ synchronized (lock) {
+ ensureOpen();
+ if (pos >= count)
+ return -1;
+ else
+ return buf[pos++];
+ }
+ }
+
+ /**
+ * Reads characters into a portion of an array.
+ * @param b Destination buffer
+ * @param off Offset at which to start storing characters
+ * @param len Maximum number of characters to read
+ * @return The actual number of characters read, or -1 if
+ * the end of the stream has been reached
+ *
+ * @exception IOException If an I/O error occurs
+ */
+ public int read(char b[], int off, int len) throws IOException {
+ synchronized (lock) {
+ ensureOpen();
+ if ((off < 0) || (off > b.length) || (len < 0) ||
+ ((off + len) > b.length) || ((off + len) < 0)) {
+ throw new IndexOutOfBoundsException();
+ } else if (len == 0) {
+ return 0;
+ }
+
+ if (pos >= count) {
+ return -1;
+ }
+ if (pos + len > count) {
+ len = count - pos;
+ }
+ if (len <= 0) {
+ return 0;
+ }
+ System.arraycopy(buf, pos, b, off, len);
+ pos += len;
+ return len;
+ }
+ }
+
+ /**
+ * Skips characters. Returns the number of characters that were skipped.
+ *
+ * <p>The <code>n</code> parameter may be negative, even though the
+ * <code>skip</code> method of the {@link Reader} superclass throws
+ * an exception in this case. If <code>n</code> is negative, then
+ * this method does nothing and returns <code>0</code>.
+ *
+ * @param n The number of characters to skip
+ * @return The number of characters actually skipped
+ * @exception IOException If the stream is closed, or an I/O error occurs
+ */
+ public long skip(long n) throws IOException {
+ synchronized (lock) {
+ ensureOpen();
+ if (pos + n > count) {
+ n = count - pos;
+ }
+ if (n < 0) {
+ return 0;
+ }
+ pos += n;
+ return n;
+ }
+ }
+
+ /**
+ * Tells whether this stream is ready to be read. Character-array readers
+ * are always ready to be read.
+ *
+ * @exception IOException If an I/O error occurs
+ */
+ public boolean ready() throws IOException {
+ synchronized (lock) {
+ ensureOpen();
+ return (count - pos) > 0;
+ }
+ }
+
+ /**
+ * Tells whether this stream supports the mark() operation, which it does.
+ */
+ public boolean markSupported() {
+ return true;
+ }
+
+ /**
+ * Marks the present position in the stream. Subsequent calls to reset()
+ * will reposition the stream to this point.
+ *
+ * @param readAheadLimit Limit on the number of characters that may be
+ * read while still preserving the mark. Because
+ * the stream's input comes from a character array,
+ * there is no actual limit; hence this argument is
+ * ignored.
+ *
+ * @exception IOException If an I/O error occurs
+ */
+ public void mark(int readAheadLimit) throws IOException {
+ synchronized (lock) {
+ ensureOpen();
+ markedPos = pos;
+ }
+ }
+
+ /**
+ * Resets the stream to the most recent mark, or to the beginning if it has
+ * never been marked.
+ *
+ * @exception IOException If an I/O error occurs
+ */
+ public void reset() throws IOException {
+ synchronized (lock) {
+ ensureOpen();
+ pos = markedPos;
+ }
+ }
+
+ /**
+ * Closes the stream and releases any system resources associated with
+ * it. Once the stream has been closed, further read(), ready(),
+ * mark(), reset(), or skip() invocations will throw an IOException.
+ * Closing a previously closed stream has no effect.
+ */
+ public void close() {
+ buf = null;
+ }
+}