FileUpload


1   /*
2   * @author                        : Neelesh
3   * @Version                       : 1.0
4   *
5   * Development Environment        : Oracle9i JDeveloper
6   * Name of the File               : FileUpload.java
7   * Creation/Modification History  :
8   *
9   * Neelesh        05-Apr-2002      Created
10  *
11  */
12  package filters.upload;
13  
14  // Java util classes
15  import java.util.StringTokenizer  ;
16  import java.util.ArrayList  ;
17  import java.util.Hashtable  ;
18  import java.util.List  ;
19  
20  // Java IO classes
21  import java.io.FileOutputStream  ;
22  import java.io.File  ;
23  import java.io.IOException  ;
24  
25  import javax.servlet.http.HttpServletRequest  ;
26  import javax.servlet.ServletInputStream  ;
27  
28  /**
29   * A simple file upload utility . The class uploads the file from a multipart 
30   * encoded form to a given directory. 
31   */
32  public class FileUpload {
33      
34    // The multipart request
35    private HttpServletRequest   req;
36  
37    // Upload dir
38    private String   dir ;
39  
40    // Name of the file being uploaded currently
41    private String   fileName;
42  
43    // Table of form fields v/s values
44    private Hashtable   map = new Hashtable  ();
45  
46    // The boundary
47    private String   boundary = "--";
48    
49    private byte[] buff= new byte[100*1024];
50    
51    // Input stream from the request
52    private ServletInputStream   in;
53    
54    // Name of the form field
55    private String   paramName;
56  
57    private String   contentType = null;
58    
59    /**
60     * The constructor takes the request and upload dir path as paramters and 
61     * uploads all the files in the request to the dir.
62     * @param <b>r</b> - multipart encoded HttpServletRequest 
63     * @param <b>uploadDir</b> - The directory to which the files should be uploaded
64     * @throws <b>IOException</b>  - If there was a problem reading the stream or
65     * writing to the file.
66     */
67    public FileUpload(HttpServletRequest   r,String   uploadDir) throws IOException   {
68      req = r;
69      dir = uploadDir;
70      upload();
71    }
72  
73    /**
74     * The method reads the next line from the servlet input stream into a byte 
75     * array and returns a String form of the array.Returns null if it reaches the 
76     * end of the stream
77     * @return <b>String</b> The next line in the stream
78     * @throws <b>IOException</b>  - If there was a problem reading the stream or
79     */
80    private String   readLine() throws IOException   {
81      int len = 0;
82      String   line = null;
83      len= in.readLine(buff,0,buff.length);
84      if (len<0) return null;
85      line = new String  (buff,0,len, "ISO-8859-1");
86  
87      return line;
88    }
89  
90    /**
91     * The method loops through the lines in the input stream and calls 
92     * writeToFile() if it encounters a file and readParam() if it encounters a
93     * form field
94     * @throws <b>IOException</b>  - If there was a problem reading the stream or
95     */
96    public void upload() throws IOException  {
97      // Set the boundary string
98      setBoundary();
99    
100     // The request stream
101     in = req.getInputStream();
102     
103     // the first line is the boundary , ignore it
104        String   line = readLine();
105     while((line= readLine())!=null) {
106       // set dispostion, param name and filename
107       setHeaders(line);
108 
109       // skip next line
110       line=readLine();
111 
112       // if there is a content-type specified, skip next line too,
113       // and this is a file, so upload it to the file system
114       if(line.toLowerCase().startsWith("content-type")){
115           contentType = line.substring(line.indexOf(":")+1).trim();
116          line=readLine();
117          writeToFile();
118          continue;
119       } else {
120          // its  a form field, read it.
121          readParam();
122       }
123     }
124   }
125 
126  /**
127   * Sets the boundary string for this request
128   */
129   private  void setBoundary()throws IOException  {
130     String   temp = req.getContentType();
131     int index = temp.indexOf("boundary=");
132     boundary += temp.substring(index+9,temp.length());
133   }
134 
135 
136  /**
137   * Reads the form field and puts it in to a table
138   */
139   private void readParam() throws IOException  {
140     String   line  = null;
141     StringBuffer   buf=  new StringBuffer  ();
142     while (!(line=readLine()).startsWith(boundary)){
143        buf.append(line);
144     }
145     line = buf.substring(0,buf.length()-2);
146     if(map.containsKey(paramName)) {
147        Object   existingValue = map.get(paramName);
148        List   valueList = null;
149        if( existingValue instanceof List  ) {
150           valueList = (List  )existingValue;
151        } else {
152           valueList=  new ArrayList  ();
153           valueList.add(existingValue);
154        }
155        valueList.add(line);
156        map.put(paramName,valueList);
157     }
158     map.put(paramName,line);
159   }
160  
161   /**
162    * Sets the content disposition, param name and file name fields
163    * @param <b>line</b> the content-disposition line
164    */
165   public  void setHeaders( String   line){
166     StringTokenizer   tokens =  new StringTokenizer  (line,";",false);
167     String   token = tokens.nextToken();
168     String   temp  = token.toLowerCase();
169     int index    = temp.indexOf("content-disposition=");
170 
171     token =  tokens.nextToken();
172     temp = token.toLowerCase();
173     index = token.indexOf("name=");
174     paramName = token.substring(index+6,token.lastIndexOf('"'));
175     fileName = null;
176 
177     if (tokens.hasMoreTokens()) {
178         token =  tokens.nextToken();
179         temp = token.toLowerCase();
180         index = token.indexOf("filename=");
181         fileName = token.substring(index+10,token.length());
182         index = fileName.lastIndexOf('/');
183         if(index<0) {
184           index = fileName.lastIndexOf('\\');
185         }
186         if(index <0) {
187           fileName = fileName.substring(0,fileName.lastIndexOf('"'));
188         } else {
189           fileName = fileName.substring(index+1,fileName.lastIndexOf('"'));
190         }
191     }
192   }
193 
194   /**
195    * Reads the file content from the stream and writes it to the local file system
196    * @throws <b>IOException</b>  - If there was a problem reading the stream 
197    */
198   private void writeToFile() throws IOException  {
199      // Open an o/p stream
200      FileOutputStream   out = new FileOutputStream   (dir+File.separator+fileName);
201 
202      // this flag checks if \r\n needs to be written to the file
203      // the servlet output stream appends these characters at the end of the 
204      // last line of the content, which should be skipped
205      // so in the loop, all \r\n but for the last line are written to the file
206      boolean writeCR = false;
207      int len = 0;
208      String   line = null;
209      map.put(paramName, dir + File.separator + fileName);
210      map.put(paramName + ".filename", fileName);
211      map.put(paramName + ".content-type", contentType);
212      
213      // for each line
214      while((len=in.readLine(buff,0,buff.length))>-1) {
215        line =  new String  (buff,0,len);
216 
217         // if end of content, break
218         if (line.startsWith(boundary)) break;
219         if(writeCR){
220           writeCR=false;
221           out.write('\r');
222           out.write('\n');
223         }
224         if(len>2 && buff[len-2]=='\r' && buff[len-1]=='\n') {
225           writeCR=true;
226           out.write(buff,0,len-2);
227         } else {
228           out.write(buff,0,len);
229         }
230       }
231             out.close();
232    }
233 
234   /**
235    * Returns the value of a request parameter as a String, or null if 
236    * the parameter does not exist.The method overrides parent method.
237    * @param <b>name</b> The name of the parameter
238    * @return <b>String </b> The value of the paramter
239    */
240   public String   getParameter( String   name ) {
241     Object   val = map.get(name);
242     if(val instanceof String  ) {
243       return (String  )val;
244     } else {
245       List   vals = (List  )val;
246       return (String  )vals.get(0);
247     }
248   }
249   
250   /**
251    * Returns an Enumeration of String objects containing the names of the 
252    * parameters contained in this request. If the  request has no parameters, 
253    * the method returns an empty Enumeration.The method overrides parent method.
254    * @return <b>Enumeration </b>of String objects, each String containing the 
255    * name of a request parameter; or an empty Enumeration if the request has 
256    * no parameters
257    */
258   public java.util.Enumeration   getParameterNames() {
259     return map.keys();
260   }
261 
262   /**
263    * Returns an array of String objects containing all of the values the given 
264    * request parameter has, or null if the parameter does not exist.
265    * The method overrides parent method.
266    * @param <b>name</b> the name of the parameter whose value is requested
267    * @return <b><String[]</b> an array of String objects containing the 
268    * parameter's values
269    */
270   public String  [] getParameterValues( String   name ) {
271 
272       if (!map.containsKey(name))
273           return null;
274       
275     Object   val = map.get(name);
276     if(val instanceof String  ){
277       return new String  []{(String  )val};
278     } else {
279       List   vals = (List  )val;
280       return (String  [])vals.toArray(new String  [vals.size()]);
281     }
282   }
283 }
284
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