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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: 502647 $
    4    * $Date: 2007-02-02 17:22:54 +0100 (Fri, 02 Feb 2007) $
    5    *
    6    * ====================================================================
    7    *
    8    *  Licensed to the Apache Software Foundation (ASF) under one or more
    9    *  contributor license agreements.  See the NOTICE file distributed with
   10    *  this work for additional information regarding copyright ownership.
   11    *  The ASF licenses this file to You under the Apache License, Version 2.0
   12    *  (the "License"); you may not use this file except in compliance with
   13    *  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, software
   18    *  distributed under the License is distributed on an "AS IS" BASIS,
   19    *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   20    *  See the License for the specific language governing permissions and
   21    *  limitations under the License.
   22    * ====================================================================
   23    *
   24    * This software consists of voluntary contributions made by many
   25    * individuals on behalf of the Apache Software Foundation.  For more
   26    * information on the Apache Software Foundation, please see
   27    * <http://www.apache.org/>.
   28    *
   29    */
   30   package org.apache.commons.httpclient.methods.multipart;
   31   
   32   import java.io.IOException;
   33   import java.io.OutputStream;
   34   import java.util.Random;
   35   
   36   import org.apache.commons.httpclient.methods.RequestEntity;
   37   import org.apache.commons.httpclient.params.HttpMethodParams;
   38   import org.apache.commons.httpclient.util.EncodingUtil;
   39   import org.apache.commons.logging.Log;
   40   import org.apache.commons.logging.LogFactory;
   41   
   42   /**
   43    * Implements a request entity suitable for an HTTP multipart POST method.
   44    * <p>
   45    * The HTTP multipart POST method is defined in section 3.3 of
   46    * <a href="http://www.ietf.org/rfc/rfc1867.txt">RFC1867</a>:
   47    * <blockquote>
   48    * The media-type multipart/form-data follows the rules of all multipart
   49    * MIME data streams as outlined in RFC 1521. The multipart/form-data contains 
   50    * a series of parts. Each part is expected to contain a content-disposition 
   51    * header where the value is "form-data" and a name attribute specifies 
   52    * the field name within the form, e.g., 'content-disposition: form-data; 
   53    * name="xxxxx"', where xxxxx is the field name corresponding to that field.
   54    * Field names originally in non-ASCII character sets may be encoded using 
   55    * the method outlined in RFC 1522.
   56    * </blockquote>
   57    * </p>
   58    * <p>This entity is designed to be used in conjunction with the 
   59    * {@link org.apache.commons.httpclient.methods.PostMethod post method} to provide
   60    * multipart posts.  Example usage:</p>
   61    * <pre>
   62    *  File f = new File("/path/fileToUpload.txt");
   63    *  PostMethod filePost = new PostMethod("http://host/some_path");
   64    *  Part[] parts = {
   65    *      new StringPart("param_name", "value"),
   66    *      new FilePart(f.getName(), f)
   67    *  };
   68    *  filePost.setRequestEntity(
   69    *      new MultipartRequestEntity(parts, filePost.getParams())
   70    *      );
   71    *  HttpClient client = new HttpClient();
   72    *  int status = client.executeMethod(filePost);
   73    * </pre>
   74    * 
   75    * @since 3.0
   76    */
   77   public class MultipartRequestEntity implements RequestEntity {
   78   
   79       private static final Log log = LogFactory.getLog(MultipartRequestEntity.class);
   80       
   81       /** The Content-Type for multipart/form-data. */
   82       private static final String MULTIPART_FORM_CONTENT_TYPE = "multipart/form-data";
   83       
   84       /**
   85        * The pool of ASCII chars to be used for generating a multipart boundary.
   86        */
   87       private static byte[] MULTIPART_CHARS = EncodingUtil.getAsciiBytes(
   88           "-_1234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ");
   89       
   90       /**
   91        * Generates a random multipart boundary string.
   92        * @return
   93        */
   94       private static byte[] generateMultipartBoundary() {
   95           Random rand = new Random();
   96           byte[] bytes = new byte[rand.nextInt(11) + 30]; // a random size from 30 to 40
   97           for (int i = 0; i < bytes.length; i++) {
   98               bytes[i] = MULTIPART_CHARS[rand.nextInt(MULTIPART_CHARS.length)];
   99           }
  100           return bytes;
  101       }
  102       
  103       /** The MIME parts as set by the constructor */
  104       protected Part[] parts;
  105       
  106       private byte[] multipartBoundary;
  107       
  108       private HttpMethodParams params;
  109       
  110       /**
  111        * Creates a new multipart entity containing the given parts.
  112        * @param parts The parts to include.
  113        * @param params The params of the HttpMethod using this entity.
  114        */
  115       public MultipartRequestEntity(Part[] parts, HttpMethodParams params) {
  116           if (parts == null) {
  117               throw new IllegalArgumentException("parts cannot be null");
  118           }
  119           if (params == null) {
  120               throw new IllegalArgumentException("params cannot be null");
  121           }
  122           this.parts = parts;
  123           this.params = params;
  124       }
  125   
  126       /**
  127        * Returns the MIME boundary string that is used to demarcate boundaries of
  128        * this part. The first call to this method will implicitly create a new
  129        * boundary string. To create a boundary string first the 
  130        * HttpMethodParams.MULTIPART_BOUNDARY parameter is considered. Otherwise 
  131        * a random one is generated.
  132        * 
  133        * @return The boundary string of this entity in ASCII encoding.
  134        */
  135       protected byte[] getMultipartBoundary() {
  136           if (multipartBoundary == null) {
  137               String temp = (String) params.getParameter(HttpMethodParams.MULTIPART_BOUNDARY);
  138               if (temp != null) {
  139                   multipartBoundary = EncodingUtil.getAsciiBytes(temp);
  140               } else {
  141                   multipartBoundary = generateMultipartBoundary();
  142               }
  143           }
  144           return multipartBoundary;
  145       }
  146   
  147       /**
  148        * Returns <code>true</code> if all parts are repeatable, <code>false</code> otherwise.
  149        * @see org.apache.commons.httpclient.methods.RequestEntity#isRepeatable()
  150        */
  151       public boolean isRepeatable() {
  152           for (int i = 0; i < parts.length; i++) {
  153               if (!parts[i].isRepeatable()) {
  154                   return false;
  155               }
  156           }
  157           return true;
  158       }
  159   
  160       /* (non-Javadoc)
  161        * @see org.apache.commons.httpclient.methods.RequestEntity#writeRequest(java.io.OutputStream)
  162        */
  163       public void writeRequest(OutputStream out) throws IOException {
  164           Part.sendParts(out, parts, getMultipartBoundary());
  165       }
  166   
  167       /* (non-Javadoc)
  168        * @see org.apache.commons.httpclient.methods.RequestEntity#getContentLength()
  169        */
  170       public long getContentLength() {
  171           try {
  172               return Part.getLengthOfParts(parts, getMultipartBoundary());            
  173           } catch (Exception e) {
  174               log.error("An exception occurred while getting the length of the parts", e);
  175               return 0;
  176           }
  177       }
  178   
  179       /* (non-Javadoc)
  180        * @see org.apache.commons.httpclient.methods.RequestEntity#getContentType()
  181        */
  182       public String getContentType() {
  183           StringBuffer buffer = new StringBuffer(MULTIPART_FORM_CONTENT_TYPE);
  184           buffer.append("; boundary=");
  185           buffer.append(EncodingUtil.getAsciiString(getMultipartBoundary()));
  186           return buffer.toString();
  187       }
  188   
  189   }

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