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 * Classic splitter of {@link OutputStream}. Named after the UNIX 'tee' command. It allows a stream to be branched off
24 * so there are now two streams.
25 */
26 public class TeeOutputStream extends ProxyOutputStream {
27
28 /**
29 * The second OutputStream to write to.
30 *
31 * TODO Make private and final in 3.0.
32 */
33 protected OutputStream branch;
34
35 /**
36 * Constructs a TeeOutputStream.
37 *
38 * @param out the main OutputStream
39 * @param branch the second OutputStream
40 */
41 public TeeOutputStream(final OutputStream out, final OutputStream branch) {
42 super(out);
43 this.branch = branch;
44 }
45
46 /**
47 * Closes both output streams.
48 * <p>
49 * If closing the main output stream throws an exception, attempt to close the branch output stream.
50 * </p>
51 *
52 * <p>
53 * If closing the main and branch output streams both throw exceptions, which exceptions is thrown by this method is
54 * currently unspecified and subject to change.
55 * </p>
56 *
57 * @throws IOException if an I/O error occurs.
58 */
59 @Override
60 public void close() throws IOException {
61 try {
62 super.close();
63 } finally {
64 this.branch.close();
65 }
66 }
67
68 /**
69 * Flushes both streams.
70 *
71 * @throws IOException if an I/O error occurs.
72 */
73 @Override
74 public void flush() throws IOException {
75 super.flush();
76 this.branch.flush();
77 }
78
79 /**
80 * Writes the bytes to both streams.
81 *
82 * @param b the bytes to write
83 * @throws IOException if an I/O error occurs.
84 */
85 @Override
86 public synchronized void write(final byte[] b) throws IOException {
87 super.write(b);
88 this.branch.write(b);
89 }
90
91 /**
92 * Writes the specified bytes to both streams.
93 *
94 * @param b the bytes to write
95 * @param off The start offset
96 * @param len The number of bytes to write
97 * @throws IOException if an I/O error occurs.
98 */
99 @Override
100 public synchronized void write(final byte[] b, final int off, final int len) throws IOException {
101 super.write(b, off, len);
102 this.branch.write(b, off, len);
103 }
104
105 /**
106 * Writes a byte to both streams.
107 *
108 * @param b the byte to write
109 * @throws IOException if an I/O error occurs.
110 */
111 @Override
112 public synchronized void write(final int b) throws IOException {
113 super.write(b);
114 this.branch.write(b);
115 }
116
117 }