1 /* 2 * Copyright (c) 1994, 2004, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package java.io; 27 28 /** 29 * This abstract class is the superclass of all classes representing 30 * an output stream of bytes. An output stream accepts output bytes 31 * and sends them to some sink. 32 * <p> 33 * Applications that need to define a subclass of 34 * <code>OutputStream</code> must always provide at least a method 35 * that writes one byte of output. 36 * 37 * @author Arthur van Hoff 38 * @see java.io.BufferedOutputStream 39 * @see java.io.ByteArrayOutputStream 40 * @see java.io.DataOutputStream 41 * @see java.io.FilterOutputStream 42 * @see java.io.InputStream 43 * @see java.io.OutputStream#write(int) 44 * @since JDK1.0 45 */ 46 public abstract class OutputStream implements Closeable, Flushable { 47 /** 48 * Writes the specified byte to this output stream. The general 49 * contract for <code>write</code> is that one byte is written 50 * to the output stream. The byte to be written is the eight 51 * low-order bits of the argument <code>b</code>. The 24 52 * high-order bits of <code>b</code> are ignored. 53 * <p> 54 * Subclasses of <code>OutputStream</code> must provide an 55 * implementation for this method. 56 * 57 * @param b the <code>byte</code>. 58 * @exception IOException if an I/O error occurs. In particular, 59 * an <code>IOException</code> may be thrown if the 60 * output stream has been closed. 61 */ 62 public abstract void write(int b) throws IOException; 63 64 /** 65 * Writes <code>b.length</code> bytes from the specified byte array 66 * to this output stream. The general contract for <code>write(b)</code> 67 * is that it should have exactly the same effect as the call 68 * <code>write(b, 0, b.length)</code>. 69 * 70 * @param b the data. 71 * @exception IOException if an I/O error occurs. 72 * @see java.io.OutputStream#write(byte[], int, int) 73 */ 74 public void write(byte b[]) throws IOException { 75 write(b, 0, b.length); 76 } 77 78 /** 79 * Writes <code>len</code> bytes from the specified byte array 80 * starting at offset <code>off</code> to this output stream. 81 * The general contract for <code>write(b, off, len)</code> is that 82 * some of the bytes in the array <code>b</code> are written to the 83 * output stream in order; element <code>b[off]</code> is the first 84 * byte written and <code>b[off+len-1]</code> is the last byte written 85 * by this operation. 86 * <p> 87 * The <code>write</code> method of <code>OutputStream</code> calls 88 * the write method of one argument on each of the bytes to be 89 * written out. Subclasses are encouraged to override this method and 90 * provide a more efficient implementation. 91 * <p> 92 * If <code>b</code> is <code>null</code>, a 93 * <code>NullPointerException</code> is thrown. 94 * <p> 95 * If <code>off</code> is negative, or <code>len</code> is negative, or 96 * <code>off+len</code> is greater than the length of the array 97 * <code>b</code>, then an <tt>IndexOutOfBoundsException</tt> is thrown. 98 * 99 * @param b the data. 100 * @param off the start offset in the data. 101 * @param len the number of bytes to write. 102 * @exception IOException if an I/O error occurs. In particular, 103 * an <code>IOException</code> is thrown if the output 104 * stream is closed. 105 */ 106 public void write(byte b[], int off, int len) throws IOException { 107 if (b == null) { 108 throw new NullPointerException(); 109 } else if ((off < 0) || (off > b.length) || (len < 0) || 110 ((off + len) > b.length) || ((off + len) < 0)) { 111 throw new IndexOutOfBoundsException(); 112 } else if (len == 0) { 113 return; 114 } 115 for (int i = 0 ; i < len ; i++) { 116 write(b[off + i]); 117 } 118 } 119 120 /** 121 * Flushes this output stream and forces any buffered output bytes 122 * to be written out. The general contract of <code>flush</code> is 123 * that calling it is an indication that, if any bytes previously 124 * written have been buffered by the implementation of the output 125 * stream, such bytes should immediately be written to their 126 * intended destination. 127 * <p> 128 * If the intended destination of this stream is an abstraction provided by 129 * the underlying operating system, for example a file, then flushing the 130 * stream guarantees only that bytes previously written to the stream are 131 * passed to the operating system for writing; it does not guarantee that 132 * they are actually written to a physical device such as a disk drive. 133 * <p> 134 * The <code>flush</code> method of <code>OutputStream</code> does nothing. 135 * 136 * @exception IOException if an I/O error occurs. 137 */ 138 public void flush() throws IOException { 139 } 140 141 /** 142 * Closes this output stream and releases any system resources 143 * associated with this stream. The general contract of <code>close</code> 144 * is that it closes the output stream. A closed stream cannot perform 145 * output operations and cannot be reopened. 146 * <p> 147 * The <code>close</code> method of <code>OutputStream</code> does nothing. 148 * 149 * @exception IOException if an I/O error occurs. 150 */ 151 public void close() throws IOException { 152 } 153 154 } 155
