Source Home >> Java Source 1.6.0 >> java.io.OutputStream V 0.09

001/*
002 * @(#)OutputStream.java	1.30 05/11/17
003 *
004 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
005 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
006 */
007
008package java.io;
009
010/**
011 * This abstract class is the superclass of all classes representing 
012 * an output stream of bytes. An output stream accepts output bytes 
013 * and sends them to some sink.
014 * <p>
015 * Applications that need to define a subclass of 
016 * <code>OutputStream</code> must always provide at least a method 
017 * that writes one byte of output.
018 *
019 * @author  Arthur van Hoff
020 * @version 1.30, 11/17/05
021 * @see     java.io.BufferedOutputStream
022 * @see     java.io.ByteArrayOutputStream
023 * @see     java.io.DataOutputStream
024 * @see     java.io.FilterOutputStream
025 * @see     java.io.InputStream
026 * @see     java.io.OutputStream#write(int)
027 * @since   JDK1.0
028 */
029public abstract class OutputStream implements Closeable, Flushable {
030    /**
031     * Writes the specified byte to this output stream. The general 
032     * contract for <code>write</code> is that one byte is written 
033     * to the output stream. The byte to be written is the eight 
034     * low-order bits of the argument <code>b</code>. The 24 
035     * high-order bits of <code>b</code> are ignored.
036     * <p>
037     * Subclasses of <code>OutputStream</code> must provide an 
038     * implementation for this method. 
039     *
040     * @param      b   the <code>byte</code>.
041     * @exception  IOException  if an I/O error occurs. In particular, 
042     *             an <code>IOException</code> may be thrown if the 
043     *             output stream has been closed.
044     */
045    public abstract void write(int b) throws IOException;
046
047    /**
048     * Writes <code>b.length</code> bytes from the specified byte array 
049     * to this output stream. The general contract for <code>write(b)</code> 
050     * is that it should have exactly the same effect as the call 
051     * <code>write(b, 0, b.length)</code>.
052     *
053     * @param      b   the data.
054     * @exception  IOException  if an I/O error occurs.
055     * @see        java.io.OutputStream#write(byte[], int, int)
056     */
057    public void write(byte b[]) throws IOException {
058	write(b, 0, b.length);
059    }
060
061    /**
062     * Writes <code>len</code> bytes from the specified byte array 
063     * starting at offset <code>off</code> to this output stream. 
064     * The general contract for <code>write(b, off, len)</code> is that 
065     * some of the bytes in the array <code>b</code> are written to the 
066     * output stream in order; element <code>b[off]</code> is the first 
067     * byte written and <code>b[off+len-1]</code> is the last byte written 
068     * by this operation.
069     * <p>
070     * The <code>write</code> method of <code>OutputStream</code> calls 
071     * the write method of one argument on each of the bytes to be 
072     * written out. Subclasses are encouraged to override this method and 
073     * provide a more efficient implementation. 
074     * <p>
075     * If <code>b</code> is <code>null</code>, a 
076     * <code>NullPointerException</code> is thrown.
077     * <p>
078     * If <code>off</code> is negative, or <code>len</code> is negative, or 
079     * <code>off+len</code> is greater than the length of the array 
080     * <code>b</code>, then an <tt>IndexOutOfBoundsException</tt> is thrown.
081     *
082     * @param      b     the data.
083     * @param      off   the start offset in the data.
084     * @param      len   the number of bytes to write.
085     * @exception  IOException  if an I/O error occurs. In particular, 
086     *             an <code>IOException</code> is thrown if the output 
087     *             stream is closed.
088     */
089    public void write(byte b[], int off, int len) throws IOException {
090	if (b == null) {
091	    throw new NullPointerException();
092	} else if ((off < 0) || (off > b.length) || (len < 0) ||
093		   ((off + len) > b.length) || ((off + len) < 0)) {
094	    throw new IndexOutOfBoundsException();
095	} else if (len == 0) {
096	    return;
097	}
098	for (int i = 0 ; i < len ; i++) {
099	    write(b[off + i]);
100	}
101    }
102
103    /**
104     * Flushes this output stream and forces any buffered output bytes 
105     * to be written out. The general contract of <code>flush</code> is 
106     * that calling it is an indication that, if any bytes previously 
107     * written have been buffered by the implementation of the output 
108     * stream, such bytes should immediately be written to their 
109     * intended destination.
110     * <p>
111     * If the intended destination of this stream is an abstraction provided by
112     * the underlying operating system, for example a file, then flushing the
113     * stream guarantees only that bytes previously written to the stream are
114     * passed to the operating system for writing; it does not guarantee that
115     * they are actually written to a physical device such as a disk drive.
116     * <p>
117     * The <code>flush</code> method of <code>OutputStream</code> does nothing.
118     *
119     * @exception  IOException  if an I/O error occurs.
120     */
121    public void flush() throws IOException {
122    }
123
124    /**
125     * Closes this output stream and releases any system resources 
126     * associated with this stream. The general contract of <code>close</code> 
127     * is that it closes the output stream. A closed stream cannot perform 
128     * output operations and cannot be reopened.
129     * <p>
130     * The <code>close</code> method of <code>OutputStream</code> does nothing.
131     *
132     * @exception  IOException  if an I/O error occurs.
133     */
134    public void close() throws IOException {
135    }
136
137}