Apple Developer Connection Student Program/ADC Tools Sampler CD Disk 3 1999.iso/Metrowerks CodeWarrior/Java Support/Java_Source/Java2/src/java/io/CharArrayWriter.java

Java Source | 1999-05-28 | 4.3 KB | 176 lines | [TEXT/CWIE]

/*
 * @(#)CharArrayWriter.java    1.11 98/06/29
 *
 * Copyright 1996-1998 by Sun Microsystems, Inc.,
 * 901 San Antonio Road, Palo Alto, California, 94303, U.S.A.
 * All rights reserved.
 *
 * This software is the confidential and proprietary information
 * of Sun Microsystems, Inc. ("Confidential Information").  You
 * shall not disclose such Confidential Information and shall use
 * it only in accordance with the terms of the license agreement
 * you entered into with Sun.
 */

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().
 *
 * @author    Herb Jellinek
 * @version     1.11, 06/29/98
 * @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.
     *
     * @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
     */
    public void writeTo(Writer out) throws IOException {
    synchronized (lock) {
        out.write(buf, 0, count);
    }
    }

    /**
     * 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.
     */
    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.
     */
    public int size() {
    return count;
    }

    /**
     * Converts input data to a string.
     * @return the string.
     */
    public String toString() {
    synchronized (lock) {
        return new String(toCharArray());
    }
    }

    /**
     * Flush the stream.
     */
    public void flush() { }

    /**
     * Close the stream.  This method does not release the buffer, since its
     * contents might still be required.
     */
    public void close() { }

}