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 }