java/8 : java/io/ByteArrayOutputStream.java

ByteArrayOutputStream
https://openjdk.java.net/
GPLv2 + Classpath Exception
/*
 * 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
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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 toByteArray() and
toString().

Closing a ByteArrayOutputStream has no effect. The methods in
this class can be called after the stream has been closed without
generating an IOException.
Author:  Arthur van Hoff
Since:   JDK1.0/**
 * 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.
/**
     * The buffer where data is stored.
     */
    protected byte buf[];

    The number of valid bytes in the buffer.
/**
     * 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.
/**
     * 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.
Params: size –   the initial size.
Throws: IllegalArgumentException – if size is negative./**
     * 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.
Params: minCapacity – the desired minimum capacity
Throws: OutOfMemoryError – if minCapacity < 0. This is interpreted as a request for the unsatisfiably large capacity (long) Integer.MAX_VALUE + (minCapacity - Integer.MAX_VALUE)./**
     * 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
/**
     * 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.
Params: minCapacity – the desired minimum capacity/**
     * 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.
Params: b –   the byte to be written./**
     * 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 len bytes from the specified byte array
starting at offset off to this byte array output stream.
Params: b –     the data.
off –   the start offset in the data.
len –   the number of bytes to write./**
     * 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 out.write(buf, 0, count).
Params: out –   the output stream to which to write the data.
Throws: IOException –  if an I/O error occurs./**
     * 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 count 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 Also: count.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.
See Also: size()
Returns:  the current contents of this output stream, as a byte array./**
     * 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.
See Also: count
Returns:  the value of the count field, which is the number
         of valid bytes in this output stream./**
     * 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 String
is a function of the character set, and hence may not be equal to the
size of the buffer.
 This method always replaces malformed-input and unmappable-character sequences with the default replacement string for the platform's default character set. The CharsetDecoder class should be used when more control over the decoding process is required. 
Returns: String decoded from the buffer's contents.
Since:  JDK1.1/**
     * 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 charset. The length of the new String is a function of the charset, and hence may not be equal
to the length of the byte array.
 This method always replaces malformed-input and unmappable-character sequences with this charset's default replacement string. The CharsetDecoder class should be used when more control over the decoding process is required. 
Params: charsetName –  the name of a supported charset
Throws: UnsupportedEncodingException – 
            If the named charset is not supported
Returns:     String decoded from the buffer's contents.
Since:      JDK1.1/**
     * 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 c in the resulting string is
constructed from the corresponding element b in the byte
array such that:
    c == (char)(((hibyte & 0xff) << 8) | (b & 0xff))

Params: hibyte –    the high byte of each resulting Unicode character.
See Also: size()
toString(String)
toString()
Deprecated: This method does not properly convert bytes into characters.
As of JDK 1.1, the preferred way to do this is via the
toString(String enc) method, which takes an encoding-name
argument, or the toString() method, which uses the
platform's default character encoding.
Returns:     the current contents of the output stream, as a string./**
     * 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 &amp; 0xff) &lt;&lt; 8) | (b &amp; 0xff))
     * </pre></blockquote>
     *
     * @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()
     */
    @Deprecated
    public synchronized String toString(int hibyte) {
        return new String(buf, hibyte, 0, count);
    }

    Closing a ByteArrayOutputStream has no effect. The methods in
this class can be called after the stream has been closed without
generating an IOException.
/**
     * 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 {
    }

}
Params:	size – the initial size.
Throws:	IllegalArgumentException – if size is negative.
Params:	minCapacity – the desired minimum capacity
Throws:	OutOfMemoryError – if `minCapacity < 0`. This is interpreted as a request for the unsatisfiably large capacity `(long) Integer.MAX_VALUE + (minCapacity - Integer.MAX_VALUE)`.
Params:	out – the output stream to which to write the data.
Throws:	IOException – if an I/O error occurs.
See Also:	size()
Returns:	the current contents of this output stream, as a byte array.
See Also:	count
Returns:	the value of the `count` field, which is the number of valid bytes in this output stream.
Returns:	String decoded from the buffer's contents.
Since:	JDK1.1
Params:	charsetName – the name of a supported `charset`
Throws:	UnsupportedEncodingException – If the named charset is not supported
Returns:	String decoded from the buffer's contents.
Since:	JDK1.1
Params:	hibyte – the high byte of each resulting Unicode character.
See Also:	size() toString(String) toString()
Deprecated:	This method does not properly convert bytes into characters. As of JDK 1.1, the preferred way to do this is via the `toString(String enc)` method, which takes an encoding-name argument, or the `toString()` method, which uses the platform's default character encoding.
Returns:	the current contents of the output stream, as a string.
/

java/ 8/ java/io/ByteArrayOutputStream.java
