001 /*
002 * Copyright 1994-2004 Sun Microsystems, Inc. All Rights Reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation. Sun designates this
008 * particular file as subject to the "Classpath" exception as provided
009 * by Sun in the LICENSE file that accompanied this code.
010 *
011 * This code is distributed in the hope that it will be useful, but WITHOUT
012 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
014 * version 2 for more details (a copy is included in the LICENSE file that
015 * accompanied this code).
016 *
017 * You should have received a copy of the GNU General Public License version
018 * 2 along with this work; if not, write to the Free Software Foundation,
019 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020 *
021 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022 * CA 95054 USA or visit www.sun.com if you need additional information or
023 * have any questions.
024 */
025
026 package java.io;
027
028 /**
029 * This abstract class is the superclass of all classes representing
030 * an output stream of bytes. An output stream accepts output bytes
031 * and sends them to some sink.
032 * <p>
033 * Applications that need to define a subclass of
034 * <code>OutputStream</code> must always provide at least a method
035 * that writes one byte of output.
036 *
037 * @author Arthur van Hoff
038 * @version 1.36, 05/05/07
039 * @see java.io.BufferedOutputStream
040 * @see java.io.ByteArrayOutputStream
041 * @see java.io.DataOutputStream
042 * @see java.io.FilterOutputStream
043 * @see java.io.InputStream
044 * @see java.io.OutputStream#write(int)
045 * @since JDK1.0
046 */
047 public abstract class OutputStream implements Closeable, Flushable {
048 /**
049 * Writes the specified byte to this output stream. The general
050 * contract for <code>write</code> is that one byte is written
051 * to the output stream. The byte to be written is the eight
052 * low-order bits of the argument <code>b</code>. The 24
053 * high-order bits of <code>b</code> are ignored.
054 * <p>
055 * Subclasses of <code>OutputStream</code> must provide an
056 * implementation for this method.
057 *
058 * @param b the <code>byte</code>.
059 * @exception IOException if an I/O error occurs. In particular,
060 * an <code>IOException</code> may be thrown if the
061 * output stream has been closed.
062 */
063 public abstract void write(int b) throws IOException;
064
065 /**
066 * Writes <code>b.length</code> bytes from the specified byte array
067 * to this output stream. The general contract for <code>write(b)</code>
068 * is that it should have exactly the same effect as the call
069 * <code>write(b, 0, b.length)</code>.
070 *
071 * @param b the data.
072 * @exception IOException if an I/O error occurs.
073 * @see java.io.OutputStream#write(byte[], int, int)
074 */
075 public void write(byte b[]) throws IOException {
076 write(b, 0, b.length);
077 }
078
079 /**
080 * Writes <code>len</code> bytes from the specified byte array
081 * starting at offset <code>off</code> to this output stream.
082 * The general contract for <code>write(b, off, len)</code> is that
083 * some of the bytes in the array <code>b</code> are written to the
084 * output stream in order; element <code>b[off]</code> is the first
085 * byte written and <code>b[off+len-1]</code> is the last byte written
086 * by this operation.
087 * <p>
088 * The <code>write</code> method of <code>OutputStream</code> calls
089 * the write method of one argument on each of the bytes to be
090 * written out. Subclasses are encouraged to override this method and
091 * provide a more efficient implementation.
092 * <p>
093 * If <code>b</code> is <code>null</code>, a
094 * <code>NullPointerException</code> is thrown.
095 * <p>
096 * If <code>off</code> is negative, or <code>len</code> is negative, or
097 * <code>off+len</code> is greater than the length of the array
098 * <code>b</code>, then an <tt>IndexOutOfBoundsException</tt> is thrown.
099 *
100 * @param b the data.
101 * @param off the start offset in the data.
102 * @param len the number of bytes to write.
103 * @exception IOException if an I/O error occurs. In particular,
104 * an <code>IOException</code> is thrown if the output
105 * stream is closed.
106 */
107 public void write(byte b[], int off, int len) throws IOException {
108 if (b == null) {
109 throw new NullPointerException();
110 } else if ((off < 0) || (off > b.length) || (len < 0)
111 || ((off + len) > b.length) || ((off + len) < 0)) {
112 throw new IndexOutOfBoundsException();
113 } else if (len == 0) {
114 return;
115 }
116 for (int i = 0; i < len; i++) {
117 write(b[off + i]);
118 }
119 }
120
121 /**
122 * Flushes this output stream and forces any buffered output bytes
123 * to be written out. The general contract of <code>flush</code> is
124 * that calling it is an indication that, if any bytes previously
125 * written have been buffered by the implementation of the output
126 * stream, such bytes should immediately be written to their
127 * intended destination.
128 * <p>
129 * If the intended destination of this stream is an abstraction provided by
130 * the underlying operating system, for example a file, then flushing the
131 * stream guarantees only that bytes previously written to the stream are
132 * passed to the operating system for writing; it does not guarantee that
133 * they are actually written to a physical device such as a disk drive.
134 * <p>
135 * The <code>flush</code> method of <code>OutputStream</code> does nothing.
136 *
137 * @exception IOException if an I/O error occurs.
138 */
139 public void flush() throws IOException {
140 }
141
142 /**
143 * Closes this output stream and releases any system resources
144 * associated with this stream. The general contract of <code>close</code>
145 * is that it closes the output stream. A closed stream cannot perform
146 * output operations and cannot be reopened.
147 * <p>
148 * The <code>close</code> method of <code>OutputStream</code> does nothing.
149 *
150 * @exception IOException if an I/O error occurs.
151 */
152 public void close() throws IOException {
153 }
154
155 }
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