content: /*
   * 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 &lt;= 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        FilterOutputStream#out
       */
      public synchronized void flush() throws IOException {
          flushBuffer();
          out.flush();
      }
  }
  