1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 */
19
20 package org.apache.commons.compress.compressors.pack200;
21
22 import java.io.FilterOutputStream;
23 import java.io.IOException;
24 import java.io.InputStream;
25 import java.io.OutputStream;
26
27 /**
28 * Provides an InputStream to read all data written to this OutputStream.
29 *
30 * @ThreadSafe
31 * @since 1.3
32 */
33 abstract class AbstractStreamBridge extends FilterOutputStream {
34
35 private InputStream inputStream;
36 private final Object inputStreamLock = new Object();
37
38 protected AbstractStreamBridge() {
39 this(null);
40 }
41
42 protected AbstractStreamBridge(final OutputStream outputStream) {
43 super(outputStream);
44 }
45
46 /**
47 * Creates the input view.
48 */
49 abstract InputStream createInputStream() throws IOException;
50
51 /**
52 * Provides the input view.
53 */
54 InputStream getInputStream() throws IOException {
55 synchronized (inputStreamLock) {
56 if (inputStream == null) {
57 inputStream = createInputStream();
58 }
59 }
60 return inputStream;
61 }
62
63 /**
64 * Closes input and output and releases all associated resources.
65 */
66 void stop() throws IOException {
67 close();
68 synchronized (inputStreamLock) {
69 if (inputStream != null) {
70 inputStream.close();
71 inputStream = null;
72 }
73 }
74 }
75 }