/*
 
* 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
   
sizethe 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
   
bthe 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
   
bthe data.
     
* @param
   
offthe start offset in the data.
     
* @param
   
lenthe 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
  
IOExceptionif 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.
     
*
     
* @seejava.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.
     
* @seejava.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.
     
* @seejava.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}
     
* @returnString 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 &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.
     
* @returnthe 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 {
    
}

}