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
37 /**
38 * Input stream that reads data without any transformation. The end of the
39 * 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, it will read until the end of the stream (until
45 * <code>-1</code> is returned).
46 *
47 * @since 4.0
48 */
49 @NotThreadSafe
50 public class IdentityInputStream extends InputStream {
51
52 private final SessionInputBuffer in;
53
54 private boolean closed = false;
55
56 /**
57 * Wraps session input stream and reads input until the the end of stream.
58 *
59 * @param in The session input buffer
60 */
61 public IdentityInputStream(final SessionInputBuffer in) {
62 super();
63 if (in == null) {
64 throw new IllegalArgumentException("Session input buffer may not be null");
65 }
66 this.in = in;
67 }
68
69 @Override
70 public int available() throws IOException {
71 if (this.in instanceof BufferInfo) {
72 return ((BufferInfo) this.in).length();
73 } else {
74 return 0;
75 }
76 }
77
78 @Override
79 public void close() throws IOException {
80 this.closed = true;
81 }
82
83 @Override
84 public int read() throws IOException {
85 if (this.closed) {
86 return -1;
87 } else {
88 return this.in.read();
89 }
90 }
91
92 @Override
93 public int read(final byte[] b, int off, int len) throws IOException {
94 if (this.closed) {
95 return -1;
96 } else {
97 return this.in.read(b, off, len);
98 }
99 }
100
101 }