1 /*
2 * ====================================================================
3 * Licensed to the Apache Software Foundation (ASF) under one
4 * or more contributor license agreements. See the NOTICE file
5 * distributed with this work for additional information
6 * regarding copyright ownership. The ASF licenses this file
7 * to you under the Apache License, Version 2.0 (the
8 * "License"); you may not use this file except in compliance
9 * with the License. You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing,
14 * software distributed under the License is distributed on an
15 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16 * KIND, either express or implied. See the License for the
17 * specific language governing permissions and limitations
18 * under the License.
19 * ====================================================================
20 *
21 * This software consists of voluntary contributions made by many
22 * individuals on behalf of the Apache Software Foundation. For more
23 * information on the Apache Software Foundation, please see
24 * <http://www.apache.org/>.
25 *
26 */
27
28 package org.apache.http.impl.io;
29
30 import java.io.IOException;
31 import java.io.OutputStream;
32
33 import org.apache.http.annotation.NotThreadSafe;
34 import org.apache.http.io.SessionOutputBuffer;
35
36 /**
37 * Output stream that writes data without any transformation. The end of
38 * the content entity is demarcated by closing the underlying connection
39 * (EOF condition). Entities transferred using this input stream can be of
40 * unlimited length.
41 * <p>
42 * Note that this class NEVER closes the underlying stream, even when close
43 * gets called. Instead, the stream will be marked as closed and no further
44 * output will be permitted.
45 *
46 * @since 4.0
47 */
48 @NotThreadSafe
49 public class IdentityOutputStream extends OutputStream {
50
51 /**
52 * Wrapped session output buffer.
53 */
54 private final SessionOutputBuffer out;
55
56 /** True if the stream is closed. */
57 private boolean closed = false;
58
59 public IdentityOutputStream(final SessionOutputBuffer out) {
60 super();
61 if (out == null) {
62 throw new IllegalArgumentException("Session output buffer may not be null");
63 }
64 this.out = out;
65 }
66
67 /**
68 * <p>Does not close the underlying socket output.</p>
69 *
70 * @throws IOException If an I/O problem occurs.
71 */
72 @Override
73 public void close() throws IOException {
74 if (!this.closed) {
75 this.closed = true;
76 this.out.flush();
77 }
78 }
79
80 @Override
81 public void flush() throws IOException {
82 this.out.flush();
83 }
84
85 @Override
86 public void write(byte[] b, int off, int len) throws IOException {
87 if (this.closed) {
88 throw new IOException("Attempted write to closed stream.");
89 }
90 this.out.write(b, off, len);
91 }
92
93 @Override
94 public void write(byte[] b) throws IOException {
95 write(b, 0, b.length);
96 }
97
98 @Override
99 public void write(int b) throws IOException {
100 if (this.closed) {
101 throw new IOException("Attempted write to closed stream.");
102 }
103 this.out.write(b);
104 }
105
106 }