--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/java/io/StringReader.java Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,201 @@
+/*
+ * 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;
+
+
+/**
+ * A character stream whose source is a string.
+ *
+ * @author Mark Reinhold
+ * @since JDK1.1
+ */
+
+public class StringReader extends Reader {
+
+ private String str;
+ private int length;
+ private int next = 0;
+ private int mark = 0;
+
+ /**
+ * Creates a new string reader.
+ *
+ * @param s String providing the character stream.
+ */
+ public StringReader(String s) {
+ this.str = s;
+ this.length = s.length();
+ }
+
+ /** Check to make sure that the stream has not been closed */
+ private void ensureOpen() throws IOException {
+ if (str == null)
+ throw new IOException("Stream closed");
+ }
+
+ /**
+ * Reads a single character.
+ *
+ * @return The character read, or -1 if the end of the stream has been
+ * reached
+ *
+ * @exception IOException If an I/O error occurs
+ */
+ public int read() throws IOException {
+ synchronized (lock) {
+ ensureOpen();
+ if (next >= length)
+ return -1;
+ return str.charAt(next++);
+ }
+ }
+
+ /**
+ * Reads characters into a portion of an array.
+ *
+ * @param cbuf Destination buffer
+ * @param off Offset at which to start writing characters
+ * @param len Maximum number of characters to read
+ *
+ * @return The 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 cbuf[], int off, int len) throws IOException {
+ synchronized (lock) {
+ ensureOpen();
+ if ((off < 0) || (off > cbuf.length) || (len < 0) ||
+ ((off + len) > cbuf.length) || ((off + len) < 0)) {
+ throw new IndexOutOfBoundsException();
+ } else if (len == 0) {
+ return 0;
+ }
+ if (next >= length)
+ return -1;
+ int n = Math.min(length - next, len);
+ str.getChars(next, next + n, cbuf, off);
+ next += n;
+ return n;
+ }
+ }
+
+ /**
+ * Skips the specified number of characters in the stream. Returns
+ * the number of characters that were skipped.
+ *
+ * <p>The <code>ns</code> parameter may be negative, even though the
+ * <code>skip</code> method of the {@link Reader} superclass throws
+ * an exception in this case. Negative values of <code>ns</code> cause the
+ * stream to skip backwards. Negative return values indicate a skip
+ * backwards. It is not possible to skip backwards past the beginning of
+ * the string.
+ *
+ * <p>If the entire string has been read or skipped, then this method has
+ * no effect and always returns 0.
+ *
+ * @exception IOException If an I/O error occurs
+ */
+ public long skip(long ns) throws IOException {
+ synchronized (lock) {
+ ensureOpen();
+ if (next >= length)
+ return 0;
+ // Bound skip by beginning and end of the source
+ long n = Math.min(length - next, ns);
+ n = Math.max(-next, n);
+ next += n;
+ return n;
+ }
+ }
+
+ /**
+ * Tells whether this stream is ready to be read.
+ *
+ * @return True if the next read() is guaranteed not to block for input
+ *
+ * @exception IOException If the stream is closed
+ */
+ public boolean ready() throws IOException {
+ synchronized (lock) {
+ ensureOpen();
+ return true;
+ }
+ }
+
+ /**
+ * 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 string, there
+ * is no actual limit, so this argument must not
+ * be negative, but is otherwise ignored.
+ *
+ * @exception IllegalArgumentException If readAheadLimit is < 0
+ * @exception IOException If an I/O error occurs
+ */
+ public void mark(int readAheadLimit) throws IOException {
+ if (readAheadLimit < 0){
+ throw new IllegalArgumentException("Read-ahead limit < 0");
+ }
+ synchronized (lock) {
+ ensureOpen();
+ mark = next;
+ }
+ }
+
+ /**
+ * Resets the stream to the most recent mark, or to the beginning of the
+ * string if it has never been marked.
+ *
+ * @exception IOException If an I/O error occurs
+ */
+ public void reset() throws IOException {
+ synchronized (lock) {
+ ensureOpen();
+ next = mark;
+ }
+ }
+
+ /**
+ * Closes the stream and releases any system resources associated with
+ * it. Once the stream has been closed, further read(),
+ * ready(), mark(), or reset() invocations will throw an IOException.
+ * Closing a previously closed stream has no effect.
+ */
+ public void close() {
+ str = null;
+ }
+}