001/* 002 * CDDL HEADER START 003 * 004 * The contents of this file are subject to the terms of the 005 * Common Development and Distribution License, Version 1.0 only 006 * (the "License"). You may not use this file except in compliance 007 * with the License. 008 * 009 * You can obtain a copy of the license at legal-notices/CDDLv1_0.txt 010 * or http://forgerock.org/license/CDDLv1.0.html. 011 * See the License for the specific language governing permissions 012 * and limitations under the License. 013 * 014 * When distributing Covered Code, include this CDDL HEADER in each 015 * file and include the License file at legal-notices/CDDLv1_0.txt. 016 * If applicable, add the following below this CDDL HEADER, with the 017 * fields enclosed by brackets "[]" replaced with your own identifying 018 * information: 019 * Portions Copyright [yyyy] [name of copyright owner] 020 * 021 * CDDL HEADER END 022 * 023 * 024 * Copyright 2006-2008 Sun Microsystems, Inc. 025 * Portions Copyright 2013 ForgeRock AS 026 */ 027package org.opends.server.types; 028 029import java.io.OutputStream; 030import java.io.PrintStream; 031 032/** 033 * This class defines a custom output stream that simply discards any 034 * data written to it. 035 */ 036@org.opends.server.types.PublicAPI( 037 stability=org.opends.server.types.StabilityLevel.UNCOMMITTED, 038 mayInstantiate=true, 039 mayExtend=false, 040 mayInvoke=true) 041public final class NullOutputStream 042 extends OutputStream 043{ 044 /** 045 * The singleton instance for this class. 046 */ 047 private static final NullOutputStream instance = 048 new NullOutputStream(); 049 050 051 052 /** 053 * The singleton print stream tied to the null output stream. 054 */ 055 private static final PrintStream printStream = 056 new PrintStream(instance); 057 058 059 060 /** 061 * Retrieves an instance of this null output stream. 062 * 063 * @return An instance of this null output stream. 064 */ 065 public static NullOutputStream instance() 066 { 067 return instance; 068 } 069 070 071 072 /** 073 * Retrieves a print stream using this null output stream. 074 * 075 * @return A print stream using this null output stream. 076 */ 077 public static PrintStream printStream() 078 { 079 return printStream; 080 } 081 082 083 /** 084 * Returns s wrapped into a {@link PrintStream} if is not null, 085 * {@link NullOutputStream#printStream()} otherwise. 086 * 087 * @param s 088 * the OutputStream to wrap into a {@link PrintStream}. Can be null. 089 * @return a PrintStream wrapping s if not null, 090 * {@link NullOutputStream#printStream()} otherwise. 091 */ 092 public static PrintStream wrapOrNullStream(OutputStream s) 093 { 094 if (s != null) 095 { 096 return new PrintStream(s); 097 } 098 return NullOutputStream.printStream(); 099 } 100 101 102 /** 103 * Creates a new instance of this null output stream. 104 */ 105 private NullOutputStream() 106 { 107 // No implementation is required. 108 } 109 110 111 112 /** 113 * Closes the output stream. This has no effect. 114 */ 115 @Override 116 public void close() 117 { 118 // No implementation is required. 119 } 120 121 122 123 /** 124 * Flushes the output stream. This has no effect. 125 */ 126 @Override 127 public void flush() 128 { 129 // No implementation is required. 130 } 131 132 133 134 /** 135 * Writes the provided data to this output stream. This has no 136 * effect. 137 * 138 * @param b The byte array containing the data to be written. 139 */ 140 @Override 141 public void write(byte[] b) 142 { 143 // No implementation is required. 144 } 145 146 147 148 /** 149 * Writes the provided data to this output stream. This has no 150 * effect. 151 * 152 * @param b The byte array containing the data to be written. 153 * @param off The offset at which the real data begins. 154 * @param len The number of bytes to be written. 155 */ 156 @Override 157 public void write(byte[] b, int off, int len) 158 { 159 // No implementation is required. 160 } 161 162 163 164 /** 165 * Writes the provided byte to this output stream. This has no 166 * effect. 167 * 168 * @param b The byte to be written. 169 */ 170 @Override 171 public void write(int b) 172 { 173 // No implementation is required. 174 } 175} 176