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.entity;
29
30 import java.io.IOException;
31 import java.io.InputStream;
32 import java.io.OutputStream;
33
34 import org.apache.http.impl.io.EmptyInputStream;
35 import org.apache.http.util.Args;
36 import org.apache.http.util.Asserts;
37
38 /**
39 * A generic streamed, non-repeatable entity that obtains its content
40 * from an {@link InputStream}.
41 *
42 * @since 4.0
43 */
44 public class BasicHttpEntity extends AbstractHttpEntity {
45
46 private InputStream content;
47 private long length;
48
49 /**
50 * Creates a new basic entity.
51 * The content is initially missing, the content length
52 * is set to a negative number.
53 */
54 public BasicHttpEntity() {
55 super();
56 this.length = -1;
57 }
58
59 @Override
60 public long getContentLength() {
61 return this.length;
62 }
63
64 /**
65 * Obtains the content, once only.
66 *
67 * @return the content, if this is the first call to this method
68 * since {@link #setContent setContent} has been called
69 *
70 * @throws IllegalStateException
71 * if the content has not been provided
72 */
73 @Override
74 public InputStream getContent() throws IllegalStateException {
75 Asserts.check(this.content != null, "Content has not been provided");
76 return this.content;
77 }
78
79 /**
80 * Tells that this entity is not repeatable.
81 *
82 * @return {@code false}
83 */
84 @Override
85 public boolean isRepeatable() {
86 return false;
87 }
88
89 /**
90 * Specifies the length of the content.
91 *
92 * @param len the number of bytes in the content, or
93 * a negative number to indicate an unknown length
94 */
95 public void setContentLength(final long len) {
96 this.length = len;
97 }
98
99 /**
100 * Specifies the content.
101 *
102 * @param inStream the stream to return with the next call to
103 * {@link #getContent getContent}
104 */
105 public void setContent(final InputStream inStream) {
106 this.content = inStream;
107 }
108
109 @Override
110 public void writeTo(final OutputStream outStream) throws IOException {
111 Args.notNull(outStream, "Output stream");
112 final InputStream inStream = getContent();
113 try {
114 int l;
115 final byte[] tmp = new byte[OUTPUT_BUFFER_SIZE];
116 while ((l = inStream.read(tmp)) != -1) {
117 outStream.write(tmp, 0, l);
118 }
119 } finally {
120 inStream.close();
121 }
122 }
123
124 @Override
125 public boolean isStreaming() {
126 return this.content != null && this.content != EmptyInputStream.INSTANCE;
127 }
128
129 }