jaroslav@682: /*
jaroslav@682:  * Copyright (c) 1994, 2003, Oracle and/or its affiliates. All rights reserved.
jaroslav@682:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
jaroslav@682:  *
jaroslav@682:  * This code is free software; you can redistribute it and/or modify it
jaroslav@682:  * under the terms of the GNU General Public License version 2 only, as
jaroslav@682:  * published by the Free Software Foundation.  Oracle designates this
jaroslav@682:  * particular file as subject to the "Classpath" exception as provided
jaroslav@682:  * by Oracle in the LICENSE file that accompanied this code.
jaroslav@682:  *
jaroslav@682:  * This code is distributed in the hope that it will be useful, but WITHOUT
jaroslav@682:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
jaroslav@682:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
jaroslav@682:  * version 2 for more details (a copy is included in the LICENSE file that
jaroslav@682:  * accompanied this code).
jaroslav@682:  *
jaroslav@682:  * You should have received a copy of the GNU General Public License version
jaroslav@682:  * 2 along with this work; if not, write to the Free Software Foundation,
jaroslav@682:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
jaroslav@682:  *
jaroslav@682:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
jaroslav@682:  * or visit www.oracle.com if you need additional information or have any
jaroslav@682:  * questions.
jaroslav@682:  */
jaroslav@682: 
jaroslav@682: package java.io;
jaroslav@682: 
jaroslav@682: /**
jaroslav@682:  * The class implements a buffered output stream. By setting up such
jaroslav@682:  * an output stream, an application can write bytes to the underlying
jaroslav@682:  * output stream without necessarily causing a call to the underlying
jaroslav@682:  * system for each byte written.
jaroslav@682:  *
jaroslav@682:  * @author  Arthur van Hoff
jaroslav@682:  * @since   JDK1.0
jaroslav@682:  */
jaroslav@682: public
jaroslav@682: class BufferedOutputStream extends FilterOutputStream {
jaroslav@682:     /**
jaroslav@682:      * The internal buffer where data is stored.
jaroslav@682:      */
jaroslav@682:     protected byte buf[];
jaroslav@682: 
jaroslav@682:     /**
jaroslav@682:      * The number of valid bytes in the buffer. This value is always
jaroslav@682:      * in the range <tt>0</tt> through <tt>buf.length</tt>; elements
jaroslav@682:      * <tt>buf[0]</tt> through <tt>buf[count-1]</tt> contain valid
jaroslav@682:      * byte data.
jaroslav@682:      */
jaroslav@682:     protected int count;
jaroslav@682: 
jaroslav@682:     /**
jaroslav@682:      * Creates a new buffered output stream to write data to the
jaroslav@682:      * specified underlying output stream.
jaroslav@682:      *
jaroslav@682:      * @param   out   the underlying output stream.
jaroslav@682:      */
jaroslav@682:     public BufferedOutputStream(OutputStream out) {
jaroslav@682:         this(out, 8192);
jaroslav@682:     }
jaroslav@682: 
jaroslav@682:     /**
jaroslav@682:      * Creates a new buffered output stream to write data to the
jaroslav@682:      * specified underlying output stream with the specified buffer
jaroslav@682:      * size.
jaroslav@682:      *
jaroslav@682:      * @param   out    the underlying output stream.
jaroslav@682:      * @param   size   the buffer size.
jaroslav@682:      * @exception IllegalArgumentException if size &lt;= 0.
jaroslav@682:      */
jaroslav@682:     public BufferedOutputStream(OutputStream out, int size) {
jaroslav@682:         super(out);
jaroslav@682:         if (size <= 0) {
jaroslav@682:             throw new IllegalArgumentException("Buffer size <= 0");
jaroslav@682:         }
jaroslav@682:         buf = new byte[size];
jaroslav@682:     }
jaroslav@682: 
jaroslav@682:     /** Flush the internal buffer */
jaroslav@682:     private void flushBuffer() throws IOException {
jaroslav@682:         if (count > 0) {
jaroslav@682:             out.write(buf, 0, count);
jaroslav@682:             count = 0;
jaroslav@682:         }
jaroslav@682:     }
jaroslav@682: 
jaroslav@682:     /**
jaroslav@682:      * Writes the specified byte to this buffered output stream.
jaroslav@682:      *
jaroslav@682:      * @param      b   the byte to be written.
jaroslav@682:      * @exception  IOException  if an I/O error occurs.
jaroslav@682:      */
jaroslav@682:     public synchronized void write(int b) throws IOException {
jaroslav@682:         if (count >= buf.length) {
jaroslav@682:             flushBuffer();
jaroslav@682:         }
jaroslav@682:         buf[count++] = (byte)b;
jaroslav@682:     }
jaroslav@682: 
jaroslav@682:     /**
jaroslav@682:      * Writes <code>len</code> bytes from the specified byte array
jaroslav@682:      * starting at offset <code>off</code> to this buffered output stream.
jaroslav@682:      *
jaroslav@682:      * <p> Ordinarily this method stores bytes from the given array into this
jaroslav@682:      * stream's buffer, flushing the buffer to the underlying output stream as
jaroslav@682:      * needed.  If the requested length is at least as large as this stream's
jaroslav@682:      * buffer, however, then this method will flush the buffer and write the
jaroslav@682:      * bytes directly to the underlying output stream.  Thus redundant
jaroslav@682:      * <code>BufferedOutputStream</code>s will not copy data unnecessarily.
jaroslav@682:      *
jaroslav@682:      * @param      b     the data.
jaroslav@682:      * @param      off   the start offset in the data.
jaroslav@682:      * @param      len   the number of bytes to write.
jaroslav@682:      * @exception  IOException  if an I/O error occurs.
jaroslav@682:      */
jaroslav@682:     public synchronized void write(byte b[], int off, int len) throws IOException {
jaroslav@682:         if (len >= buf.length) {
jaroslav@682:             /* If the request length exceeds the size of the output buffer,
jaroslav@682:                flush the output buffer and then write the data directly.
jaroslav@682:                In this way buffered streams will cascade harmlessly. */
jaroslav@682:             flushBuffer();
jaroslav@682:             out.write(b, off, len);
jaroslav@682:             return;
jaroslav@682:         }
jaroslav@682:         if (len > buf.length - count) {
jaroslav@682:             flushBuffer();
jaroslav@682:         }
jaroslav@682:         System.arraycopy(b, off, buf, count, len);
jaroslav@682:         count += len;
jaroslav@682:     }
jaroslav@682: 
jaroslav@682:     /**
jaroslav@682:      * Flushes this buffered output stream. This forces any buffered
jaroslav@682:      * output bytes to be written out to the underlying output stream.
jaroslav@682:      *
jaroslav@682:      * @exception  IOException  if an I/O error occurs.
jaroslav@682:      * @see        java.io.FilterOutputStream#out
jaroslav@682:      */
jaroslav@682:     public synchronized void flush() throws IOException {
jaroslav@682:         flushBuffer();
jaroslav@682:         out.flush();
jaroslav@682:     }
jaroslav@682: }