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
18 package org.apache.logging.log4j.core.util;
19
20 import java.io.IOException;
21 import java.io.OutputStream;
22
23 /**
24 * Writes all data to the famous <b>/dev/null</b>.
25 * <p>
26 * This output stream has no destination (file/socket etc.) and all bytes written to it are ignored and lost.
27 * </p>
28 * Originally from Apache Commons IO.
29 *
30 * @since 2.3
31 */
32 public class NullOutputStream extends OutputStream {
33
34 private static final NullOutputStream INSTANCE = new NullOutputStream();
35
36 /**
37 * @deprecated Deprecated in 2.7: use {@link #getInstance()}.
38 */
39 @Deprecated
40 public static final NullOutputStream NULL_OUTPUT_STREAM = INSTANCE;
41
42 /**
43 * Gets the singleton instance.
44 *
45 * @return the singleton instance.
46 */
47 public static NullOutputStream getInstance() {
48 return INSTANCE;
49 }
50
51 private NullOutputStream() {
52 // do nothing
53 }
54
55 /**
56 * Does nothing - output to <code>/dev/null</code>.
57 *
58 * @param b
59 * The bytes to write
60 * @param off
61 * The start offset
62 * @param len
63 * The number of bytes to write
64 */
65 @Override
66 public void write(final byte[] b, final int off, final int len) {
67 // to /dev/null
68 }
69
70 /**
71 * Does nothing - output to <code>/dev/null</code>.
72 *
73 * @param b
74 * The byte to write
75 */
76 @Override
77 public void write(final int b) {
78 // to /dev/null
79 }
80
81 /**
82 * Does nothing - output to <code>/dev/null</code>.
83 *
84 * @param b
85 * The bytes to write
86 * @throws IOException
87 * never
88 */
89 @Override
90 public void write(final byte[] b) throws IOException {
91 // to /dev/null
92 }
93 }