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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/AbstractHttpEntity.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.IOException;
     35 
     36 import org.apache.http.Header;
     37 import org.apache.http.HttpEntity;
     38 import org.apache.http.message.BasicHeader;
     39 import org.apache.http.protocol.HTTP;
     40 
     41 /**
     42  * Abstract base class for entities.
     43  * Provides the commonly used attributes for streamed and self-contained
     44  * implementations of {@link HttpEntity HttpEntity}.
     45  *
     46  * @author <a href="mailto:oleg at ural.ru">Oleg Kalnichevski</a>
     47  *
     48  * @version $Revision: 496070 $
     49  *
     50  * @since 4.0
     51  */
     52 public abstract class AbstractHttpEntity implements HttpEntity {
     53 
     54     /**
     55      * The Content-Type header.
     56      * Returned by {@link #getContentType getContentType},
     57      * unless that method is overridden.
     58      */
     59     protected Header contentType;
     60 
     61     /**
     62      * The Content-Encoding header.
     63      * Returned by {@link #getContentEncoding getContentEncoding},
     64      * unless that method is overridden.
     65      */
     66     protected Header contentEncoding;
     67 
     68     /**
     69      * The 'chunked' flag.
     70      * Returned by {@link #isChunked isChunked},
     71      * unless that method is overridden.
     72      */
     73     protected boolean chunked;
     74 
     75 
     76     /**
     77      * Protected default constructor.
     78      * The attributes of the created object remain
     79      * <code>null</code> and <code>false</code>, respectively.
     80      */
     81     protected AbstractHttpEntity() {
     82         super();
     83     }
     84 
     85 
     86     /**
     87      * Obtains the Content-Type header.
     88      * The default implementation returns the value of the
     89      * {@link #contentType contentType} attribute.
     90      *
     91      * @return  the Content-Type header, or <code>null</code>
     92      */
     93     public Header getContentType() {
     94         return this.contentType;
     95     }
     96 
     97 
     98     /**
     99      * Obtains the Content-Encoding header.
    100      * The default implementation returns the value of the
    101      * {@link #contentEncoding contentEncoding} attribute.
    102      *
    103      * @return  the Content-Encoding header, or <code>null</code>
    104      */
    105     public Header getContentEncoding() {
    106         return this.contentEncoding;
    107     }
    108 
    109     /**
    110      * Obtains the 'chunked' flag.
    111      * The default implementation returns the value of the
    112      * {@link #chunked chunked} attribute.
    113      *
    114      * @return  the 'chunked' flag
    115      */
    116     public boolean isChunked() {
    117         return this.chunked;
    118     }
    119 
    120 
    121     /**
    122      * Specifies the Content-Type header.
    123      * The default implementation sets the value of the
    124      * {@link #contentType contentType} attribute.
    125      *
    126      * @param contentType       the new Content-Encoding header, or
    127      *                          <code>null</code> to unset
    128      */
    129     public void setContentType(final Header contentType) {
    130         this.contentType = contentType;
    131     }
    132 
    133     /**
    134      * Specifies the Content-Type header, as a string.
    135      * The default implementation calls
    136      * {@link #setContentType(Header) setContentType(Header)}.
    137      *
    138      * @param ctString     the new Content-Type header, or
    139      *                     <code>null</code> to unset
    140      */
    141     public void setContentType(final String ctString) {
    142         Header h = null;
    143         if (ctString != null) {
    144             h = new BasicHeader(HTTP.CONTENT_TYPE, ctString);
    145         }
    146         setContentType(h);
    147     }
    148 
    149 
    150     /**
    151      * Specifies the Content-Encoding header.
    152      * The default implementation sets the value of the
    153      * {@link #contentEncoding contentEncoding} attribute.
    154      *
    155      * @param contentEncoding   the new Content-Encoding header, or
    156      *                          <code>null</code> to unset
    157      */
    158     public void setContentEncoding(final Header contentEncoding) {
    159         this.contentEncoding = contentEncoding;
    160     }
    161 
    162     /**
    163      * Specifies the Content-Encoding header, as a string.
    164      * The default implementation calls
    165      * {@link #setContentEncoding(Header) setContentEncoding(Header)}.
    166      *
    167      * @param ceString     the new Content-Encoding header, or
    168      *                     <code>null</code> to unset
    169      */
    170     public void setContentEncoding(final String ceString) {
    171         Header h = null;
    172         if (ceString != null) {
    173             h = new BasicHeader(HTTP.CONTENT_ENCODING, ceString);
    174         }
    175         setContentEncoding(h);
    176     }
    177 
    178 
    179     /**
    180      * Specifies the 'chunked' flag.
    181      * The default implementation sets the value of the
    182      * {@link #chunked chunked} attribute.
    183      *
    184      * @param b         the new 'chunked' flag
    185      */
    186     public void setChunked(boolean b) {
    187         this.chunked = b;
    188     }
    189 
    190 
    191     /**
    192      * Does not consume anything.
    193      * The default implementation does nothing if
    194      * {@link HttpEntity#isStreaming isStreaming}
    195      * returns <code>false</code>, and throws an exception
    196      * if it returns <code>true</code>.
    197      * This removes the burden of implementing
    198      * an empty method for non-streaming entities.
    199      *
    200      * @throws IOException      in case of an I/O problem
    201      * @throws UnsupportedOperationException
    202      *          if a streaming subclass does not override this method
    203      */
    204     public void consumeContent()
    205         throws IOException, UnsupportedOperationException{
    206         if (isStreaming()) {
    207             throw new UnsupportedOperationException
    208                 ("streaming entity does not implement consumeContent()");
    209         }
    210     } // consumeContent
    211 
    212 
    213 } // class AbstractHttpEntity
    214