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.InputStream;
32
33 import org.apache.http.annotation.NotThreadSafe;
34 import org.apache.http.io.BufferInfo;
35 import org.apache.http.io.SessionInputBuffer;
36 import org.apache.http.util.Args;
37
38 /**
39 * Input stream that reads data without any transformation. The end of the
40 * content entity is demarcated by closing the underlying connection
41 * (EOF condition). Entities transferred using this input stream can be of
42 * unlimited length.
43 * <p>
44 * Note that this class NEVER closes the underlying stream, even when close
45 * gets called. Instead, it will read until the end of the stream (until
46 * <code>-1</code> is returned).
47 *
48 * @since 4.0
49 */
50 @NotThreadSafe
51 public class IdentityInputStream extends InputStream {
52
53 private final SessionInputBuffer in;
54
55 private boolean closed = false;
56
57 /**
58 * Wraps session input stream and reads input until the the end of stream.
59 *
60 * @param in The session input buffer
61 */
62 public IdentityInputStream(final SessionInputBuffer in) {
63 super();
64 this.in = Args.notNull(in, "Session input buffer");
65 }
66
67 @Override
68 public int available() throws IOException {
69 if (this.in instanceof BufferInfo) {
70 return ((BufferInfo) this.in).length();
71 } else {
72 return 0;
73 }
74 }
75
76 @Override
77 public void close() throws IOException {
78 this.closed = true;
79 }
80
81 @Override
82 public int read() throws IOException {
83 if (this.closed) {
84 return -1;
85 } else {
86 return this.in.read();
87 }
88 }
89
90 @Override
91 public int read(final byte[] b, final int off, final int len) throws IOException {
92 if (this.closed) {
93 return -1;
94 } else {
95 return this.in.read(b, off, len);
96 }
97 }
98
99 }