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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.hc.core5.http.io.entity;
29  
30  import java.io.ByteArrayInputStream;
31  import java.io.ByteArrayOutputStream;
32  import java.io.IOException;
33  import java.io.InputStream;
34  import java.io.OutputStream;
35  
36  import org.apache.hc.core5.http.HttpEntity;
37  import org.apache.hc.core5.util.Args;
38  
39  /**
40   * A wrapping entity that buffers it content if necessary.
41   * The buffered entity is always repeatable.
42   * If the wrapped entity is repeatable itself, calls are passed through.
43   * If the wrapped entity is not repeatable, the content is read into a
44   * buffer once and provided from there as often as required.
45   *
46   * @since 4.0
47   */
48  public class BufferedHttpEntity extends HttpEntityWrapper {
49  
50      private final byte[] buffer;
51  
52      /**
53       * Creates a new buffered entity wrapper.
54       *
55       * @param entity   the entity to wrap, not null
56       * @throws IllegalArgumentException if wrapped is null
57       */
58      public BufferedHttpEntity(final HttpEntity entity) throws IOException {
59          super(entity);
60          if (!entity.isRepeatable() || entity.getContentLength() < 0) {
61              final ByteArrayOutputStream out = new ByteArrayOutputStream();
62              entity.writeTo(out);
63              out.flush();
64              this.buffer = out.toByteArray();
65          } else {
66              this.buffer = null;
67          }
68      }
69  
70      @Override
71      public long getContentLength() {
72          if (this.buffer != null) {
73              return this.buffer.length;
74          }
75          return super.getContentLength();
76      }
77  
78      @Override
79      public InputStream getContent() throws IOException {
80          if (this.buffer != null) {
81              return new ByteArrayInputStream(this.buffer);
82          }
83          return super.getContent();
84      }
85  
86      /**
87       * Tells that this entity does not have to be chunked.
88       *
89       * @return  {@code false}
90       */
91      @Override
92      public boolean isChunked() {
93          return (buffer == null) && super.isChunked();
94      }
95  
96      /**
97       * Tells that this entity is repeatable.
98       *
99       * @return  {@code true}
100      */
101     @Override
102     public boolean isRepeatable() {
103         return true;
104     }
105 
106 
107     @Override
108     public void writeTo(final OutputStream outstream) throws IOException {
109         Args.notNull(outstream, "Output stream");
110         if (this.buffer != null) {
111             outstream.write(this.buffer);
112         } else {
113             super.writeTo(outstream);
114         }
115     }
116 
117 
118     // non-javadoc, see interface HttpEntity
119     @Override
120     public boolean isStreaming() {
121         return (buffer == null) && super.isStreaming();
122     }
123 
124 } // class BufferedHttpEntity