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.IOException;
20 import java.io.OutputStream;
21
22 /**
23 * Throws an IOException on all attempts to write to the stream.
24 * <p>
25 * Typically uses of this class include testing for corner cases in methods that accept an output stream and acting as a sentinel value instead of a
26 * {@code null} output stream.
27 * </p>
28 *
29 * @since 1.4
30 */
31 public class ClosedOutputStream extends OutputStream {
32
33 /**
34 * The singleton instance.
35 *
36 * @since 2.12.0
37 */
38 public static final ClosedOutputStream INSTANCE = new ClosedOutputStream();
39
40 /**
41 * The singleton instance.
42 *
43 * @deprecated Use {@link #INSTANCE}.
44 */
45 @Deprecated
46 public static final ClosedOutputStream CLOSED_OUTPUT_STREAM = INSTANCE;
47
48 /**
49 * Construct a new instance.
50 */
51 public ClosedOutputStream() {
52 // empty
53 }
54
55 /**
56 * Throws an {@link IOException} to indicate that the stream is closed.
57 *
58 * @throws IOException always thrown
59 */
60 @Override
61 public void flush() throws IOException {
62 throw new IOException("flush() failed: stream is closed");
63 }
64
65 /**
66 * Throws an {@link IOException} to indicate that the stream is closed.
67 *
68 * @param b ignored
69 * @param off ignored
70 * @param len ignored
71 * @throws IOException always thrown
72 */
73 @Override
74 public void write(final byte b[], final int off, final int len) throws IOException {
75 throw new IOException("write(byte[], int, int) failed: stream is closed");
76 }
77
78 /**
79 * Throws an {@link IOException} to indicate that the stream is closed.
80 *
81 * @param b ignored
82 * @throws IOException always thrown
83 */
84 @Override
85 public void write(final int b) throws IOException {
86 throw new IOException("write(int) failed: stream is closed");
87 }
88 }