1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 package org.apache.commons.io.output; 18 19 import java.io.Writer; 20 21 /** 22 * Never writes data. Calls never go beyond this class. 23 * <p> 24 * This {@link Writer} has no destination (file/socket etc.) and all characters written to it are ignored and lost. 25 * </p> 26 */ 27 public class NullWriter extends Writer { 28 29 /** 30 * The singleton instance. 31 * 32 * @since 2.12.0 33 */ 34 public static final NullWriter INSTANCE = new NullWriter(); 35 36 /** 37 * The singleton instance. 38 * 39 * @deprecated Use {@link #INSTANCE}. 40 */ 41 @Deprecated 42 public static final NullWriter NULL_WRITER = INSTANCE; 43 44 /** 45 * Constructs a new NullWriter. 46 * 47 * @deprecated Use {@link #INSTANCE}. 48 */ 49 @Deprecated 50 public NullWriter() { 51 } 52 53 /** 54 * Does nothing - output to {@code /dev/null}. 55 * @param c The character to write 56 * @return this writer 57 * @since 2.0 58 */ 59 @Override 60 public Writer append(final char c) { 61 //to /dev/null 62 return this; 63 } 64 65 /** 66 * Does nothing - output to {@code /dev/null}. 67 * @param csq The character sequence to write 68 * @return this writer 69 * @since 2.0 70 */ 71 @Override 72 public Writer append(final CharSequence csq) { 73 //to /dev/null 74 return this; 75 } 76 77 /** 78 * Does nothing - output to {@code /dev/null}. 79 * @param csq The character sequence to write 80 * @param start The index of the first character to write 81 * @param end The index of the first character to write (exclusive) 82 * @return this writer 83 * @since 2.0 84 */ 85 @Override 86 public Writer append(final CharSequence csq, final int start, final int end) { 87 //to /dev/null 88 return this; 89 } 90 91 /** @see java.io.Writer#close() */ 92 @Override 93 public void close() { 94 //to /dev/null 95 } 96 97 /** @see java.io.Writer#flush() */ 98 @Override 99 public void flush() { 100 //to /dev/null 101 } 102 103 /** 104 * Does nothing - output to {@code /dev/null}. 105 * @param chr The characters to write 106 */ 107 @Override 108 public void write(final char[] chr) { 109 //to /dev/null 110 } 111 112 /** 113 * Does nothing - output to {@code /dev/null}. 114 * @param chr The characters to write 115 * @param st The start offset 116 * @param end The number of characters to write 117 */ 118 @Override 119 public void write(final char[] chr, final int st, final int end) { 120 //to /dev/null 121 } 122 123 /** 124 * Does nothing - output to {@code /dev/null}. 125 * @param idx The character to write 126 */ 127 @Override 128 public void write(final int idx) { 129 //to /dev/null 130 } 131 132 /** 133 * Does nothing - output to {@code /dev/null}. 134 * @param str The string to write 135 */ 136 @Override 137 public void write(final String str) { 138 //to /dev/null 139 } 140 141 /** 142 * Does nothing - output to {@code /dev/null}. 143 * @param str The string to write 144 * @param st The start offset 145 * @param end The number of characters to write 146 */ 147 @Override 148 public void write(final String str, final int st, final int end) { 149 //to /dev/null 150 } 151 152 }