/*
 * @(#)ByteArrayOutputStream.java	1.23 97/02/24
 * 
 * Copyright (c) 1995, 1996 Sun Microsystems, Inc. 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.
 * 
 * SUN MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF THE
 * SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
 * PURPOSE, OR NON-INFRINGEMENT. SUN SHALL NOT BE LIABLE FOR ANY DAMAGES
 * SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR DISTRIBUTING
 * THIS SOFTWARE OR ITS DERIVATIVES.
 * 
 * CopyrightVersion 1.1_beta
 * 
 */

package java.io;


/**
 * This class implements an output stream in which the data is 
 * written into a byte array. The buffer automatically grows as data 
 * is written to it. 
 * The data can be retrieved using <code>toByteArray()</code> and
 * <code>toString()</code>.
 *
 * @author  Arthur van Hoff
 * @version 1.23, 24 Feb 1997
 * @since   JDK1.0
 */

public class ByteArrayOutputStream extends OutputStream {

    /** 
     * The buffer where data is stored. 
     */
    protected byte buf[];

    /**
     * The number of valid bytes in the buffer. 
     */
    protected int count;

    /**
     * Creates a new byte array output stream. The buffer capacity is 
     * initially 32 bytes, though its size increases if necessary. 
     */
    public ByteArrayOutputStream() {
	this(32);
    }

    /**
     * Creates a new byte array output stream, with a buffer capacity of 
     * the specified size, in bytes. 
     *
     * @param   size   the initial size.
     */
    public ByteArrayOutputStream(int size) {
	buf = new byte[size];
    }

    /**
     * Writes the specified byte to this byte array output stream. 
     *
     * @param   b   the byte to be written.
     */
    public synchronized void write(int b) {
	int newcount = count + 1;
	if (newcount > buf.length) {
	    byte newbuf[] = new byte[Math.max(buf.length << 1, newcount)];
	    System.arraycopy(buf, 0, newbuf, 0, count);
	    buf = newbuf;
	}
	buf[count] = (byte)b;
	count = newcount;
    }

    /**
     * Writes <code>len</code> bytes from the specified byte array 
     * starting at offset <code>off</code> to this byte array output stream.
     *
     * @param   b     the data.
     * @param   off   the start offset in the data.
     * @param   len   the number of bytes to write.
     */
    public synchronized void write(byte b[], int off, int len) {
	int newcount = count + len;
	if (newcount > buf.length) {
	    byte newbuf[] = new byte[Math.max(buf.length << 1, newcount)];
	    System.arraycopy(buf, 0, newbuf, 0, count);
	    buf = newbuf;
	}
	System.arraycopy(b, off, buf, count, len);
	count = newcount;
    }

    /**
     * Writes the complete contents of this byte array output stream to 
     * the specified output stream argument, as if by calling the output 
     * stream's write method using <code>out.write(buf, 0, count)</code>.
     *
     * @param      out   the output stream to which to write the data.
     * @exception  IOException  if an I/O error occurs.
     */
    public synchronized void writeTo(OutputStream out) throws IOException {
	out.write(buf, 0, count);
    }

    /**
     * Resets the <code>count</code> field of this byte array output 
     * stream to zero, so that all currently accumulated output in the 
     * ouput stream is discarded. The output stream can be used again, 
     * reusing the already allocated buffer space. 
     *
     * @see     java.io.ByteArrayInputStream#count
     */
    public synchronized void reset() {
	count = 0;
    }

    /**
     * Creates a newly allocated byte array. Its size is the current 
     * size of this output stream and the valid contents of the buffer 
     * have been copied into it. 
     *
     * @return  the current contents of this output stream, as a byte array.
     * @see     java.io.ByteArrayOutputStream#size()
     */
    public synchronized byte toByteArray()[] {
	byte newbuf[] = new byte[count];
	System.arraycopy(buf, 0, newbuf, 0, count);
	return newbuf;
    }

    /**
     * Returns the current size of the buffer.
     *
     * @return  the value of the <code>count</code> field, which is the number
     *          of valid bytes in this output stream.
     * @see     java.io.ByteArrayOutputStream#count
     */
    public int size() {
	return count;
    }

    /**
     * Converts the buffer's contents into a string, translating bytes into
     * characters according to the platform's default character encoding.
     */
    public String toString() {
	return new String(buf, 0, count);
    }

    /**
     * Converts the buffer's contents into a string, translating bytes into
     * characters according to the specified character encoding.
     *
     * @param   enc  a character-encoding name.
     * @since   JDK1.1
     */
    public String toString(String enc) throws UnsupportedEncodingException {
	return new String(buf, 0, count, enc);
    }

    /**
     * Creates a newly allocated string. Its size is the current size of 
     * the output stream and the valid contents of the buffer have been 
     * copied into it. Each character <i>c</i> in the resulting string is 
     * constructed from the corresponding element <i>b</i> in the byte 
     * array such that:
     * <ul><code>
     *     c == (char)(((hibyte &amp; 0xff) &lt;&lt; 8) | (b &amp; 0xff))
     * </code></ul>
     *
     * @deprecated This method does not properly convert bytes into characters.
     * As of JDK&nbsp;1.1, the preferred way to do this is via the
     * <code>toString(String enc)</code> method, which takes an encoding-name
     * argument, or the <code>toString()</code> method, which uses the
     * platform's default character encoding.
     *
     * @param      hibyte    the high byte of each resulting Unicode character.
     * @return     the current contents of the output stream, as a string.
     * @see        java.io.ByteArrayOutputStream#size()
     * @see        java.io.ByteArrayOutputStream#toString(String)
     * @see        java.io.ByteArrayOutputStream#toString()
     */
    public String toString(int hibyte) {
	return new String(buf, hibyte, 0, count);
    }

}
