/*

  * Copyright (c) 1994, 2003, 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;

 /**

  * The class implements a buffered output stream. By setting up such

  * an output stream, an application can write bytes to the underlying

  * output stream without necessarily causing a call to the underlying

  * system for each byte written.

  *

  * @author  Arthur van Hoff

  * @since   JDK1.0

  */

 public

 class BufferedOutputStream extends FilterOutputStream {

     /**

      * The internal buffer where data is stored.

      */

     protected byte buf[];

     /**

      * The number of valid bytes in the buffer. This value is always

      * in the range <tt>0</tt> through <tt>buf.length</tt>; elements

      * <tt>buf[0]</tt> through <tt>buf[count-1]</tt> contain valid

      * byte data.

      */

     protected int count;

     /**

      * Creates a new buffered output stream to write data to the

      * specified underlying output stream.

      *

      * @param   out   the underlying output stream.

      */

     public BufferedOutputStream(OutputStream out) {

         this(out, 8192);

     }

     /**

      * Creates a new buffered output stream to write data to the

      * specified underlying output stream with the specified buffer

      * size.

      *

      * @param   out    the underlying output stream.

      * @param   size   the buffer size.

      * @exception IllegalArgumentException if size <= 0.

      */

     public BufferedOutputStream(OutputStream out, int size) {

         super(out);

         if (size <= 0) {

             throw new IllegalArgumentException("Buffer size <= 0");

         }

         buf = new byte[size];

     }

     /** Flush the internal buffer */

     private void flushBuffer() throws IOException {

         if (count > 0) {

             out.write(buf, 0, count);

             count = 0;

         }

     }

     /**

      * Writes the specified byte to this buffered output stream.

      *

      * @param      b   the byte to be written.

      * @exception  IOException  if an I/O error occurs.

      */

     public synchronized void write(int b) throws IOException {

         if (count >= buf.length) {

             flushBuffer();

         }

         buf[count++] = (byte)b;

     }

     /**

      * Writes <code>len</code> bytes from the specified byte array

      * starting at offset <code>off</code> to this buffered output stream.

      *

      * <p> Ordinarily this method stores bytes from the given array into this

      * stream's buffer, flushing the buffer to the underlying output stream as

      * needed.  If the requested length is at least as large as this stream's

      * buffer, however, then this method will flush the buffer and write the

      * bytes directly to the underlying output stream.  Thus redundant

      * <code>BufferedOutputStream</code>s will not copy data unnecessarily.

      *

      * @param      b     the data.

      * @param      off   the start offset in the data.

      * @param      len   the number of bytes to write.

      * @exception  IOException  if an I/O error occurs.

      */

     public synchronized void write(byte b[], int off, int len) throws IOException {

         if (len >= buf.length) {

             /* If the request length exceeds the size of the output buffer,

                flush the output buffer and then write the data directly.

                In this way buffered streams will cascade harmlessly. */

             flushBuffer();

             out.write(b, off, len);

             return;

         }

         if (len > buf.length - count) {

             flushBuffer();

         }

         System.arraycopy(b, off, buf, count, len);

         count += len;

     }

     /**

      * Flushes this buffered output stream. This forces any buffered

      * output bytes to be written out to the underlying output stream.

      *

      * @exception  IOException  if an I/O error occurs.

      * @see        java.io.FilterOutputStream#out

      */

     public synchronized void flush() throws IOException {

         flushBuffer();

         out.flush();

     }

 }