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Some of you have troubles getting JSP upload functions in your code working. Here is upload code example that you can drop in to a JSP file in your webapp directory to quickly check if uploading works.

Common cause of problems is lack of write privileges in a directory where you are trying to upload to. It will upload to your current web app directory defined in filePath variable. The code uses commons-fileupload-1.2.2.jar and commons-io-2.4.jar in WEB-INF/lib to make it simple. Uploading code without these fileupload classes is bigger and not so easy readable. Here is the content of uploadtest.jsp.

<%@ page import="java.io.*,java.util.*, javax.servlet.*" %>
<%@ page import="javax.servlet.http.*" %>
<%@ page import="org.apache.commons.fileupload.*" %>
<%@ page import="org.apache.commons.fileupload.disk.*" %>
<%@ page import="org.apache.commons.fileupload.servlet.*" %>
<%@ page import="org.apache.commons.io.output.*" %>
<%
ServletContext context = pageContext.getServletContext();
String filePath = context.getRealPath(request.getContextPath()) + "/";
File file; 
int maxFileSize = 5000 * 1024; 
int maxMemSize = maxFileSize;
String contentType = request.getContentType();
    
if (contentType != null && (contentType.indexOf("multipart/form-data") >= 0)) {
     DiskFileItemFactory factory = new DiskFileItemFactory();
     factory.setSizeThreshold(maxMemSize); 
     factory.setRepository(new File("/tmp"));
     ServletFileUpload upload = new ServletFileUpload(factory);
     upload.setSizeMax(maxFileSize);
     try { 
       List fileItems = upload.parseRequest(request);
     Iterator i = fileItems.iterator();
     while (i.hasNext ()) {
       FileItem fi = (FileItem)i.next();
     if (!fi.isFormField ()) {
        String fieldName = fi.getFieldName();
      String fileName = fi.getName();
      if (fileName == "") out.println("You forgot to choose a file. <a href=''>Try again</a>");
      boolean isInMemory = fi.isInMemory();
      long sizeInBytes = fi.getSize();
     if( fileName.lastIndexOf("\\") >= 0 ) {
       file = new File(filePath + fileName.substring(fileName.lastIndexOf("\\")));
     } else { 
      file = new File(filePath + fileName.substring(fileName.lastIndexOf("\\")+1));
      }
     fi.write(file) ;
      out.println("Uploaded Filename: " + filePath + fileName + ", sizeInBytes = " + sizeInBytes + "<br/><a href=''>Upload again</a>");
      }
     }
     } catch(Exception ex) { System.out.println(ex); }
    } else {
     %> 
     <p>One needs commons-fileupload.x.x.jar and commons-io-x.x.jar fils in classpath (e.g. WEB-INF/lib).<br/> 
     You can download these from http://commons.apache.org/fileupload/ and http://commons.apache.org/io/</p>
     <h3>File Upload Test (uploaded file is to be saved under current context)</h3>
     <p><% out.println("Destination path: " + filePath); %></p>
     <form enctype="multipart/form-data" action="uploadtest.jsp" method="post"><table>
     <tr><td align="left">Select a file to upload:</td></tr>
     <tr><td align="left"><input type="file" name="filename" size="50"></td></tr>
     <tr><td align="left"><input type="submit" name="Submit" value="Upload">
     <input type="reset" name="Reset" value="Cancel"></td></tr>
     </table></form>
     <%  
} %>