- /*
- * @(#)CharArrayWriter.java 1.23 04/07/16
- *
- * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
- * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
- */
-
- package java.io;
-
- /**
- * This class implements a character buffer that can be used as an Writer.
- * The buffer automatically grows when data is written to the stream. The data
- * can be retrieved using toCharArray() and toString().
- * <P>
- * Note: Invoking close() on this class has no effect, and methods
- * of this class can be called after the stream has closed
- * without generating an IOException.
- *
- * @author Herb Jellinek
- * @version 1.23, 07/16/04
- * @since JDK1.1
- */
- public
- class CharArrayWriter extends Writer {
- /**
- * The buffer where data is stored.
- */
- protected char buf[];
-
- /**
- * The number of chars in the buffer.
- */
- protected int count;
-
- /**
- * Creates a new CharArrayWriter.
- */
- public CharArrayWriter() {
- this(32);
- }
-
- /**
- * Creates a new CharArrayWriter with the specified initial size.
- *
- * @param initialSize an int specifying the initial buffer size.
- * @exception IllegalArgumentException if initialSize is negative
- */
- public CharArrayWriter(int initialSize) {
- if (initialSize < 0) {
- throw new IllegalArgumentException("Negative initial size: "
- + initialSize);
- }
- buf = new char[initialSize];
- }
-
- /**
- * Writes a character to the buffer.
- */
- public void write(int c) {
- synchronized (lock) {
- int newcount = count + 1;
- if (newcount > buf.length) {
- char newbuf[] = new char[Math.max(buf.length << 1, newcount)];
- System.arraycopy(buf, 0, newbuf, 0, count);
- buf = newbuf;
- }
- buf[count] = (char)c;
- count = newcount;
- }
- }
-
- /**
- * Writes characters to the buffer.
- * @param c the data to be written
- * @param off the start offset in the data
- * @param len the number of chars that are written
- */
- public void write(char c[], int off, int len) {
- if ((off < 0) || (off > c.length) || (len < 0) ||
- ((off + len) > c.length) || ((off + len) < 0)) {
- throw new IndexOutOfBoundsException();
- } else if (len == 0) {
- return;
- }
- synchronized (lock) {
- int newcount = count + len;
- if (newcount > buf.length) {
- char newbuf[] = new char[Math.max(buf.length << 1, newcount)];
- System.arraycopy(buf, 0, newbuf, 0, count);
- buf = newbuf;
- }
- System.arraycopy(c, off, buf, count, len);
- count = newcount;
- }
- }
-
- /**
- * Write a portion of a string to the buffer.
- * @param str String to be written from
- * @param off Offset from which to start reading characters
- * @param len Number of characters to be written
- */
- public void write(String str, int off, int len) {
- synchronized (lock) {
- int newcount = count + len;
- if (newcount > buf.length) {
- char newbuf[] = new char[Math.max(buf.length << 1, newcount)];
- System.arraycopy(buf, 0, newbuf, 0, count);
- buf = newbuf;
- }
- str.getChars(off, off + len, buf, count);
- count = newcount;
- }
- }
-
- /**
- * Writes the contents of the buffer to another character stream.
- *
- * @param out the output stream to write to
- * @throws IOException If an I/O error occurs.
- */
- public void writeTo(Writer out) throws IOException {
- synchronized (lock) {
- out.write(buf, 0, count);
- }
- }
-
- /**
- * Appends the specified character sequence to this writer.
- *
- * <p> An invocation of this method of the form <tt>out.append(csq)</tt>
- * behaves in exactly the same way as the invocation
- *
- * <pre>
- * out.write(csq.toString()) </pre>
- *
- * <p> Depending on the specification of <tt>toString</tt> for the
- * character sequence <tt>csq</tt>, the entire sequence may not be
- * appended. For instance, invoking the <tt>toString</tt> method of a
- * character buffer will return a subsequence whose content depends upon
- * the buffer's position and limit.
- *
- * @param csq
- * The character sequence to append. If <tt>csq</tt> is
- * <tt>null</tt>, then the four characters <tt>"null"</tt> are
- * appended to this writer.
- *
- * @return This writer
- *
- * @since 1.5
- */
- public CharArrayWriter append(CharSequence csq) {
- String s = (csq == null ? "null" : csq.toString());
- write(s, 0, s.length());
- return this;
- }
-
- /**
- * Appends a subsequence of the specified character sequence to this writer.
- *
- * <p> An invocation of this method of the form <tt>out.append(csq, start,
- * end)</tt> when <tt>csq</tt> is not <tt>null</tt>, behaves in
- * exactly the same way as the invocation
- *
- * <pre>
- * out.write(csq.subSequence(start, end).toString()) </pre>
- *
- * @param csq
- * The character sequence from which a subsequence will be
- * appended. If <tt>csq</tt> is <tt>null</tt>, then characters
- * will be appended as if <tt>csq</tt> contained the four
- * characters <tt>"null"</tt>.
- *
- * @param start
- * The index of the first character in the subsequence
- *
- * @param end
- * The index of the character following the last character in the
- * subsequence
- *
- * @return This writer
- *
- * @throws IndexOutOfBoundsException
- * If <tt>start</tt> or <tt>end</tt> are negative, <tt>start</tt>
- * is greater than <tt>end</tt>, or <tt>end</tt> is greater than
- * <tt>csq.length()</tt>
- *
- * @since 1.5
- */
- public CharArrayWriter append(CharSequence csq, int start, int end) {
- String s = (csq == null ? "null" : csq).subSequence(start, end).toString();
- write(s, 0, s.length());
- return this;
- }
-
- /**
- * Appends the specified character to this writer.
- *
- * <p> An invocation of this method of the form <tt>out.append(c)</tt>
- * behaves in exactly the same way as the invocation
- *
- * <pre>
- * out.write(c) </pre>
- *
- * @param c
- * The 16-bit character to append
- *
- * @return This writer
- *
- * @since 1.5
- */
- public CharArrayWriter append(char c) {
- write(c);
- return this;
- }
-
- /**
- * Resets the buffer so that you can use it again without
- * throwing away the already allocated buffer.
- */
- public void reset() {
- count = 0;
- }
-
- /**
- * Returns a copy of the input data.
- *
- * @return an array of chars copied from the input data.
- */
- public char toCharArray()[] {
- synchronized (lock) {
- char newbuf[] = new char[count];
- System.arraycopy(buf, 0, newbuf, 0, count);
- return newbuf;
- }
- }
-
- /**
- * Returns the current size of the buffer.
- *
- * @return an int representing the current size of the buffer.
- */
- public int size() {
- return count;
- }
-
- /**
- * Converts input data to a string.
- * @return the string.
- */
- public String toString() {
- synchronized (lock) {
- return new String(buf, 0, count);
- }
- }
-
- /**
- * Flush the stream.
- */
- public void flush() { }
-
- /**
- * Close the stream. This method does not release the buffer, since its
- * contents might still be required. Note: Invoking this method in this class
- * will have no effect.
- */
- public void close() { }
-
- }