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 import org.apache.http.util.Args;
36
37 /**
38 * Output stream that writes data without any transformation. The end of
39 * the content entity is demarcated by closing the underlying connection
40 * (EOF condition). Entities transferred using this input stream can be of
41 * unlimited length.
42 * <p>
43 * Note that this class NEVER closes the underlying stream, even when close
44 * gets called. Instead, the stream will be marked as closed and no further
45 * output will be permitted.
46 *
47 * @since 4.0
48 */
49 @NotThreadSafe
50 public class IdentityOutputStream extends OutputStream {
51
52 /**
53 * Wrapped session output buffer.
54 */
55 private final SessionOutputBuffer out;
56
57 /** True if the stream is closed. */
58 private boolean closed = false;
59
60 public IdentityOutputStream(final SessionOutputBuffer out) {
61 super();
62 this.out = Args.notNull(out, "Session output buffer");
63 }
64
65 /**
66 * <p>Does not close the underlying socket output.</p>
67 *
68 * @throws IOException If an I/O problem occurs.
69 */
70 @Override
71 public void close() throws IOException {
72 if (!this.closed) {
73 this.closed = true;
74 this.out.flush();
75 }
76 }
77
78 @Override
79 public void flush() throws IOException {
80 this.out.flush();
81 }
82
83 @Override
84 public void write(final byte[] b, final int off, final int len) throws IOException {
85 if (this.closed) {
86 throw new IOException("Attempted write to closed stream.");
87 }
88 this.out.write(b, off, len);
89 }
90
91 @Override
92 public void write(final byte[] b) throws IOException {
93 write(b, 0, b.length);
94 }
95
96 @Override
97 public void write(final int b) throws IOException {
98 if (this.closed) {
99 throw new IOException("Attempted write to closed stream.");
100 }
101 this.out.write(b);
102 }
103
104 }