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
32package org.apache.http.entity;
33
34import java.io.IOException;
35
36import org.apache.http.Header;
37import org.apache.http.HttpEntity;
38import org.apache.http.message.BasicHeader;
39import 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 */
52public 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