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	/*
	* Copyright (c) 1994, 2013, Oracle and/or its affiliates. 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. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package java.io;

	import java.util.Arrays;

	/**
	* 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>.
	* <p>
	* Closing a <tt>ByteArrayOutputStream</tt> has no effect. The methods in
	* this class can be called after the stream has been closed without
	* generating an <tt>IOException</tt>.
	*
	* @author Arthur van Hoff
	* @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.
	* @exception IllegalArgumentException if size is negative.
	*/
	public ByteArrayOutputStream(int size) {
	if (size < 0) {
	throw new IllegalArgumentException("Negative initial size: "
	+ size);
	}
	buf = new byte[size];
	}

	/**
	* Increases the capacity if necessary to ensure that it can hold
	* at least the number of elements specified by the minimum
	* capacity argument.
	*
	* @param minCapacity the desired minimum capacity
	* @throws OutOfMemoryError if {@code minCapacity < 0}. This is
	* interpreted as a request for the unsatisfiably large capacity
	* {@code (long) Integer.MAX_VALUE + (minCapacity - Integer.MAX_VALUE)}.
	*/
	private void ensureCapacity(int minCapacity) {
	// overflow-conscious code
	if (minCapacity - buf.length > 0)
	grow(minCapacity);
	}

	/**
	* The maximum size of array to allocate.
	* Some VMs reserve some header words in an array.
	* Attempts to allocate larger arrays may result in
	* OutOfMemoryError: Requested array size exceeds VM limit
	*/
	private static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8;

	/**
	* Increases the capacity to ensure that it can hold at least the
	* number of elements specified by the minimum capacity argument.
	*
	* @param minCapacity the desired minimum capacity
	*/
	private void grow(int minCapacity) {
	// overflow-conscious code
	int oldCapacity = buf.length;
	int newCapacity = oldCapacity << 1;
	if (newCapacity - minCapacity < 0)
	newCapacity = minCapacity;
	if (newCapacity - MAX_ARRAY_SIZE > 0)
	newCapacity = hugeCapacity(minCapacity);
	buf = Arrays.copyOf(buf, newCapacity);
	}

	private static int hugeCapacity(int minCapacity) {
	if (minCapacity < 0) // overflow
	throw new OutOfMemoryError();
	return (minCapacity > MAX_ARRAY_SIZE) ?
	Integer.MAX_VALUE :
	MAX_ARRAY_SIZE;
	}

	/**
	* Writes the specified byte to this byte array output stream.
	*
	* @param b the byte to be written.
	*/
	public synchronized void write(int b) {
	ensureCapacity(count + 1);
	buf[count] = (byte) b;
	count += 1;
	}

	/**
	* 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) {
	if ((off < 0) \|\| (off > b.length) \|\| (len < 0) \|\|
	((off + len) - b.length > 0)) {
	throw new IndexOutOfBoundsException();
	}
	ensureCapacity(count + len);
	System.arraycopy(b, off, buf, count, len);
	count += len;
	}

	/**
	* 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
	* output 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()[] {
	return Arrays.copyOf(buf, count);
	}

	/**
	* 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 synchronized int size() {
	return count;
	}

	/**
	* Converts the buffer's contents into a string decoding bytes using the
	* platform's default character set. The length of the new <tt>String</tt>
	* is a function of the character set, and hence may not be equal to the
	* size of the buffer.
	*
	* <p> This method always replaces malformed-input and unmappable-character
	* sequences with the default replacement string for the platform's
	* default character set. The {@linkplain java.nio.charset.CharsetDecoder}
	* class should be used when more control over the decoding process is
	* required.
	*
	* @return String decoded from the buffer's contents.
	* @since JDK1.1
	*/
	public synchronized String toString() {
	return new String(buf, 0, count);
	}

	/**
	* Converts the buffer's contents into a string by decoding the bytes using
	* the named {@link java.nio.charset.Charset charset}. The length of the new
	* <tt>String</tt> is a function of the charset, and hence may not be equal
	* to the length of the byte array.
	*
	* <p> This method always replaces malformed-input and unmappable-character
	* sequences with this charset's default replacement string. The {@link
	* java.nio.charset.CharsetDecoder} class should be used when more control
	* over the decoding process is required.
	*
	* @param charsetName the name of a supported
	* {@link java.nio.charset.Charset charset}
	* @return String decoded from the buffer's contents.
	* @exception UnsupportedEncodingException
	* If the named charset is not supported
	* @since JDK1.1
	*/
	public synchronized String toString(String charsetName)
	throws UnsupportedEncodingException
	{
	return new String(buf, 0, count, charsetName);
	}

	/**
	* 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:
	* <blockquote><pre>
	* c == (char)(((hibyte & 0xff) << 8) \| (b & 0xff))
	* </pre></blockquote>
	*
	* @deprecated This method does not properly convert bytes into characters.
	* As of JDK 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()
	*/
	@Deprecated
	public synchronized String toString(int hibyte) {
	return new String(buf, hibyte, 0, count);
	}

	/**
	* Closing a <tt>ByteArrayOutputStream</tt> has no effect. The methods in
	* this class can be called after the stream has been closed without
	* generating an <tt>IOException</tt>.
	*/
	public void close() throws IOException {
	}

	}

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