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.io.BufferInfo;
34 import org.apache.http.io.SessionInputBuffer;
35 import org.apache.http.util.Args;
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} is returned).
46 *
47 * @since 4.0
48 */
49 public class IdentityInputStream extends InputStream {
50
51 private final SessionInputBuffer in;
52
53 private boolean closed = false;
54
55 /**
56 * Wraps session input stream and reads input until the the end of stream.
57 *
58 * @param in The session input buffer
59 */
60 public IdentityInputStream(final SessionInputBuffer in) {
61 super();
62 this.in = Args.notNull(in, "Session input buffer");
63 }
64
65 @Override
66 public int available() throws IOException {
67 if (this.in instanceof BufferInfo) {
68 return ((BufferInfo) this.in).length();
69 }
70 return 0;
71 }
72
73 @Override
74 public void close() throws IOException {
75 this.closed = true;
76 }
77
78 @Override
79 public int read() throws IOException {
80 return this.closed ? -1 : this.in.read();
81 }
82
83 @Override
84 public int read(final byte[] b, final int off, final int len) throws IOException {
85 return this.closed ? -1 : this.in.read(b, off, len);
86 }
87
88 }