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      1 /*
      2  * $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk/module-main/src/main/java/org/apache/http/entity/BufferedHttpEntity.java $
      3  * $Revision: 496070 $
      4  * $Date: 2007-01-14 04:18:34 -0800 (Sun, 14 Jan 2007) $
      5  *
      6  * ====================================================================
      7  * Licensed to the Apache Software Foundation (ASF) under one
      8  * or more contributor license agreements.  See the NOTICE file
      9  * distributed with this work for additional information
     10  * regarding copyright ownership.  The ASF licenses this file
     11  * to you under the Apache License, Version 2.0 (the
     12  * "License"); you may not use this file except in compliance
     13  * with the License.  You may obtain a copy of the License at
     14  *
     15  *   http://www.apache.org/licenses/LICENSE-2.0
     16  *
     17  * Unless required by applicable law or agreed to in writing,
     18  * software distributed under the License is distributed on an
     19  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
     20  * KIND, either express or implied.  See the License for the
     21  * specific language governing permissions and limitations
     22  * under the License.
     23  * ====================================================================
     24  *
     25  * This software consists of voluntary contributions made by many
     26  * individuals on behalf of the Apache Software Foundation.  For more
     27  * information on the Apache Software Foundation, please see
     28  * <http://www.apache.org/>.
     29  *
     30  */
     31 
     32 package org.apache.http.entity;
     33 
     34 import java.io.ByteArrayInputStream;
     35 import java.io.IOException;
     36 import java.io.InputStream;
     37 import java.io.OutputStream;
     38 
     39 import org.apache.http.HttpEntity;
     40 import org.apache.http.util.EntityUtils;
     41 
     42 /**
     43  * A wrapping entity that buffers it content if necessary.
     44  * The buffered entity is always repeatable.
     45  * If the wrapped entity is repeatable itself, calls are passed through.
     46  * If the wrapped entity is not repeatable, the content is read into a
     47  * buffer once and provided from there as often as required.
     48  *
     49  * @author <a href="mailto:oleg at ural.ru">Oleg Kalnichevski</a>
     50  *
     51  * @version $Revision: 496070 $
     52  *
     53  * @since 4.0
     54  */
     55 public class BufferedHttpEntity extends HttpEntityWrapper {
     56 
     57     private final byte[] buffer;
     58 
     59     public BufferedHttpEntity(final HttpEntity entity) throws IOException {
     60         super(entity);
     61         if (!entity.isRepeatable() || entity.getContentLength() < 0) {
     62             this.buffer = EntityUtils.toByteArray(entity);
     63         } else {
     64             this.buffer = null;
     65         }
     66     }
     67 
     68     public long getContentLength() {
     69         if (this.buffer != null) {
     70             return this.buffer.length;
     71         } else {
     72             return wrappedEntity.getContentLength();
     73         }
     74     }
     75 
     76     public InputStream getContent() throws IOException {
     77         if (this.buffer != null) {
     78             return new ByteArrayInputStream(this.buffer);
     79         } else {
     80             return wrappedEntity.getContent();
     81         }
     82     }
     83 
     84     /**
     85      * Tells that this entity does not have to be chunked.
     86      *
     87      * @return  <code>false</code>
     88      */
     89     public boolean isChunked() {
     90         return (buffer == null) && wrappedEntity.isChunked();
     91     }
     92 
     93     /**
     94      * Tells that this entity is repeatable.
     95      *
     96      * @return  <code>true</code>
     97      */
     98     public boolean isRepeatable() {
     99         return true;
    100     }
    101 
    102 
    103     public void writeTo(final OutputStream outstream) throws IOException {
    104         if (outstream == null) {
    105             throw new IllegalArgumentException("Output stream may not be null");
    106         }
    107         if (this.buffer != null) {
    108             outstream.write(this.buffer);
    109         } else {
    110             wrappedEntity.writeTo(outstream);
    111         }
    112     }
    113 
    114 
    115     // non-javadoc, see interface HttpEntity
    116     public boolean isStreaming() {
    117         return (buffer == null) && wrappedEntity.isStreaming();
    118     }
    119 
    120 } // class BufferedHttpEntity
    121