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 * https://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.IOException;
20 import java.io.OutputStream;
21
22 import org.apache.commons.io.IOUtils;
23
24 /**
25 * Never writes data. Calls never go beyond this class.
26 * <p>
27 * This output stream has no destination and all bytes written to it are ignored.
28 * </p>
29 */
30 public class NullOutputStream extends OutputStream {
31
32 /**
33 * The singleton instance.
34 *
35 * @since 2.12.0
36 */
37 public static final NullOutputStream INSTANCE = new NullOutputStream();
38
39 /**
40 * The singleton instance.
41 *
42 * @deprecated Use {@link #INSTANCE}.
43 */
44 @Deprecated
45 public static final NullOutputStream NULL_OUTPUT_STREAM = INSTANCE;
46
47 /**
48 * Deprecated in favor of {@link #INSTANCE}.
49 * <p>
50 * TODO: Will be private in 3.0.
51 * </p>
52 *
53 * @deprecated Use {@link #INSTANCE}.
54 */
55 @Deprecated
56 public NullOutputStream() {
57 // empty
58 }
59
60 /**
61 * Does nothing.
62 *
63 * @param b The This method ignores this parameter.
64 * @throws IOException This method never throws any exceptions.
65 */
66 @Override
67 public void write(final byte[] b) throws IOException {
68 // noop
69 }
70
71 /**
72 * No-op operation.
73 *
74 * <p>Validates the arguments but does not write the data.</p>
75 *
76 * @param b The byte array to write from, not {@code null}.
77 * @param off The offset to start at.
78 * @param len The number of bytes to write.
79 * @throws NullPointerException If {@code b} is {@code null}.
80 * @throws IndexOutOfBoundsException If {@code off} or {@code len} are negative, {@code off + len} is greater than
81 * {@code b.length}.
82 */
83 @Override
84 public void write(final byte[] b, final int off, final int len) {
85 IOUtils.checkFromIndexSize(b, off, len);
86 }
87
88 /**
89 * Does nothing.
90 *
91 * @param b This method ignores this parameter.
92 */
93 @Override
94 public void write(final int b) {
95 // noop
96 }
97
98 }