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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.nio.entity;
29  
30  import java.io.IOException;
31  import java.io.InputStream;
32  import java.nio.ByteBuffer;
33  import java.nio.channels.Channels;
34  import java.nio.channels.ReadableByteChannel;
35  
36  import org.apache.http.HttpEntity;
37  import org.apache.http.annotation.NotThreadSafe;
38  import org.apache.http.nio.ContentEncoder;
39  import org.apache.http.nio.IOControl;
40  import org.apache.http.util.Args;
41  
42  /**
43   * Basic implementation of {@link HttpAsyncContentProducer} that relies on
44   * inefficient and potentially blocking I/O operation redirection through
45   * {@link Channels#newChannel(java.io.InputStream)}.
46   *
47   * @since 4.2
48   */
49  @NotThreadSafe
50  public class EntityAsyncContentProducer implements HttpAsyncContentProducer {
51  
52      private final HttpEntity entity;
53      private final ByteBuffer buffer;
54      private ReadableByteChannel channel;
55  
56      public EntityAsyncContentProducer(final HttpEntity entity) {
57          super();
58          Args.notNull(entity, "HTTP entity");
59          this.entity = entity;
60          this.buffer = ByteBuffer.allocate(4096);
61      }
62  
63      @Override
64      public void produceContent(
65              final ContentEncoder encoder, final IOControl ioctrl) throws IOException {
66          if (this.channel == null) {
67              this.channel = Channels.newChannel(this.entity.getContent());
68          }
69          final int i = this.channel.read(this.buffer);
70          this.buffer.flip();
71          encoder.write(this.buffer);
72          final boolean buffering = this.buffer.hasRemaining();
73          this.buffer.compact();
74          if (i == -1 && !buffering) {
75              encoder.complete();
76              close();
77          }
78      }
79  
80      @Override
81      public boolean isRepeatable() {
82          return this.entity.isRepeatable();
83      }
84  
85      @Override
86      public void close() throws IOException {
87          final ReadableByteChannel local = this.channel;
88          this.channel = null;
89          if (local != null) {
90              local.close();
91          }
92          if (this.entity.isStreaming()) {
93              final InputStream instream = this.entity.getContent();
94              instream.close();
95          }
96      }
97  
98      @Override
99      public String toString() {
100         return this.entity.toString();
101     }
102 
103 }