/*
* Copyright 1994-2003 Sun Microsystems, Inc. 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. Sun designates this
* particular file as subject to the "Classpath" exception as provided
* by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.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
* @version 1.40, 05/05/07
* @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();
}
}
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