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.io.SessionOutputBuffer;
34 import org.apache.http.util.Args;
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 public class IdentityOutputStream extends OutputStream {
49
50 /**
51 * Wrapped session output buffer.
52 */
53 private final SessionOutputBuffer out;
54
55 /** True if the stream is closed. */
56 private boolean closed = false;
57
58 public IdentityOutputStream(final SessionOutputBuffer out) {
59 super();
60 this.out = Args.notNull(out, "Session output buffer");
61 }
62
63 /**
64 * <p>Does not close the underlying socket output.</p>
65 *
66 * @throws IOException If an I/O problem occurs.
67 */
68 @Override
69 public void close() throws IOException {
70 if (!this.closed) {
71 this.closed = true;
72 this.out.flush();
73 }
74 }
75
76 @Override
77 public void flush() throws IOException {
78 this.out.flush();
79 }
80
81 @Override
82 public void write(final byte[] b, final int off, final int len) throws IOException {
83 if (this.closed) {
84 throw new IOException("Attempted write to closed stream.");
85 }
86 this.out.write(b, off, len);
87 }
88
89 @Override
90 public void write(final byte[] b) throws IOException {
91 write(b, 0, b.length);
92 }
93
94 @Override
95 public void write(final int b) throws IOException {
96 if (this.closed) {
97 throw new IOException("Attempted write to closed stream.");
98 }
99 this.out.write(b);
100 }
101
102 }