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1   /*
2    * $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//httpclient/src/java/org/apache/commons/httpclient/methods/multipart/MultipartRequestEntity.java,v 1.1 2004/10/06 03:39:59 mbecke Exp $
3    * $Revision: 327791 $
4    * $Date: 2005-10-23 09:27:39 -0400 (Sun, 23 Oct 2005) $
5    *
6    * ====================================================================
7    *
8    *  Copyright 2002-2004 The Apache Software Foundation
9    *
10   *  Licensed under the Apache License, Version 2.0 (the "License");
11   *  you may not use this file except in compliance with the License.
12   *  You may obtain a copy of the License at
13   *
14   *      http://www.apache.org/licenses/LICENSE-2.0
15   *
16   *  Unless required by applicable law or agreed to in writing, software
17   *  distributed under the License is distributed on an "AS IS" BASIS,
18   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
19   *  See the License for the specific language governing permissions and
20   *  limitations under the License.
21   * ====================================================================
22   *
23   * This software consists of voluntary contributions made by many
24   * individuals on behalf of the Apache Software Foundation.  For more
25   * information on the Apache Software Foundation, please see
26   * <http://www.apache.org/>.
27   *
28   */
29  package org.apache.commons.httpclient.methods.multipart;
30  
31  import java.io.IOException;
32  import java.io.OutputStream;
33  import java.util.Random;
34  
35  import org.apache.commons.httpclient.methods.RequestEntity;
36  import org.apache.commons.httpclient.params.HttpMethodParams;
37  import org.apache.commons.httpclient.util.EncodingUtil;
38  import org.apache.commons.logging.Log;
39  import org.apache.commons.logging.LogFactory;
40  
41  /***
42   * Implements a request entity suitable for an HTTP multipart POST method.
43   * <p>
44   * The HTTP multipart POST method is defined in section 3.3 of
45   * <a href="http://www.ietf.org/rfc/rfc1867.txt">RFC1867</a>:
46   * <blockquote>
47   * The media-type multipart/form-data follows the rules of all multipart
48   * MIME data streams as outlined in RFC 1521. The multipart/form-data contains 
49   * a series of parts. Each part is expected to contain a content-disposition 
50   * header where the value is "form-data" and a name attribute specifies 
51   * the field name within the form, e.g., 'content-disposition: form-data; 
52   * name="xxxxx"', where xxxxx is the field name corresponding to that field.
53   * Field names originally in non-ASCII character sets may be encoded using 
54   * the method outlined in RFC 1522.
55   * </blockquote>
56   * </p>
57   * <p>This entity is designed to be used in conjunction with the 
58   * {@link org.apache.commons.httpclient.methods.PostMethod post method} to provide
59   * multipart posts.  Example usage:</p>
60   * <code>
61   *  File f = new File("/path/fileToUpload.txt");
62   *  PostMethod filePost = new PostMethod("http://host/some_path");
63   *  Part[] parts = {
64   *      new StringPart("param_name", "value"),
65   *      new FilePart(f.getName(), f)
66   *  };
67   *  filePost.setRequestEntity(
68   *      new MultipartRequestEntity(parts, filePost.getParams())
69   *      );
70   *  HttpClient client = new HttpClient();
71   *  int status = client.executeMethod(filePost);
72   * </code>
73   * 
74   * @since 3.0
75   */
76  public class MultipartRequestEntity implements RequestEntity {
77  
78      private static final Log log = LogFactory.getLog(MultipartRequestEntity.class);
79      
80      /*** The Content-Type for multipart/form-data. */
81      private static final String MULTIPART_FORM_CONTENT_TYPE = "multipart/form-data";
82      
83      /***
84       * The pool of ASCII chars to be used for generating a multipart boundary.
85       */
86      private static byte[] MULTIPART_CHARS = EncodingUtil.getAsciiBytes(
87          "-_1234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ");
88      
89      /***
90       * Generates a random multipart boundary string.
91       * @return
92       */
93      private static byte[] generateMultipartBoundary() {
94          Random rand = new Random();
95          byte[] bytes = new byte[rand.nextInt(11) + 30]; // a random size from 30 to 40
96          for (int i = 0; i < bytes.length; i++) {
97              bytes[i] = MULTIPART_CHARS[rand.nextInt(MULTIPART_CHARS.length)];
98          }
99          return bytes;
100     }
101     
102     /*** The MIME parts as set by the constructor */
103     protected Part[] parts;
104     
105     private byte[] multipartBoundary;
106     
107     private HttpMethodParams params;
108     
109     /***
110      * Creates a new multipart entity containing the given parts.
111      * @param parts The parts to include.
112      * @param params The params of the HttpMethod using this entity.
113      */
114     public MultipartRequestEntity(Part[] parts, HttpMethodParams params) {
115         if (parts == null) {
116             throw new IllegalArgumentException("parts cannot be null");
117         }
118         if (params == null) {
119             throw new IllegalArgumentException("params cannot be null");
120         }
121         this.parts = parts;
122         this.params = params;
123     }
124 
125     /***
126      * Returns the MIME boundary string that is used to demarcate boundaries of
127      * this part. The first call to this method will implicitly create a new
128      * boundary string. To create a boundary string first the 
129      * HttpMethodParams.MULTIPART_BOUNDARY parameter is considered. Otherwise 
130      * a random one is generated.
131      * 
132      * @return The boundary string of this entity in ASCII encoding.
133      */
134     protected byte[] getMultipartBoundary() {
135         if (multipartBoundary == null) {
136             String temp = (String) params.getParameter(HttpMethodParams.MULTIPART_BOUNDARY);
137             if (temp != null) {
138                 multipartBoundary = EncodingUtil.getAsciiBytes(temp);
139             } else {
140                 multipartBoundary = generateMultipartBoundary();
141             }
142         }
143         return multipartBoundary;
144     }
145 
146     /***
147      * Returns <code>true</code> if all parts are repeatable, <code>false</code> otherwise.
148      * @see org.apache.commons.httpclient.methods.RequestEntity#isRepeatable()
149      */
150     public boolean isRepeatable() {
151         for (int i = 0; i < parts.length; i++) {
152             if (!parts[i].isRepeatable()) {
153                 return false;
154             }
155         }
156         return true;
157     }
158 
159     /* (non-Javadoc)
160      * @see org.apache.commons.httpclient.methods.RequestEntity#writeRequest(java.io.OutputStream)
161      */
162     public void writeRequest(OutputStream out) throws IOException {
163         Part.sendParts(out, parts, getMultipartBoundary());
164     }
165 
166     /* (non-Javadoc)
167      * @see org.apache.commons.httpclient.methods.RequestEntity#getContentLength()
168      */
169     public long getContentLength() {
170         try {
171             return Part.getLengthOfParts(parts, getMultipartBoundary());            
172         } catch (Exception e) {
173             log.error("An exception occurred while getting the length of the parts", e);
174             return 0;
175         }
176     }
177 
178     /* (non-Javadoc)
179      * @see org.apache.commons.httpclient.methods.RequestEntity#getContentType()
180      */
181     public String getContentType() {
182         StringBuffer buffer = new StringBuffer(MULTIPART_FORM_CONTENT_TYPE);
183         buffer.append("; boundary=");
184         buffer.append(EncodingUtil.getAsciiString(getMultipartBoundary()));
185         return buffer.toString();
186     }
187 
188 }