Uploading a file to be saved in database

Question

Hi all,
I have a web application which users access through browser. There is a screen where I list certificates of a person from database. My requirement is that for a particular certificate, user will select a file and click Attach button. I then need to upload this file and saved in database for that certificate.
What are the steps involved in uploading a file to be saved in database?
<form>
<input type="hidden" name="certificate_id" />
<input type="file" name="certificate_file" />
<input type="submit" value="Attach" />
</form>Edited by: srhcan on Jun 16, 2012 8:48 AM

Answer 1

Thanks guys for your help.
My environment is Eclipse Indigo and JBoss 4.2.0. I have created a simple web application in to test Apache Commons FileUpload. This app consist of just one jsp and one servlet. The jsp has the input type file and is submitted to the servlet. The servlet prints out the file info. The 2 Commons jars fileupload and io are in WEB-INF\lib folder.
I have tested it successfully when I run the Jboss from within Eclipse.
But when I run the JBoss outside of Eclipse, I get this error message from servlet:
2012-06-19 19:54:55,405 ERROR [org.apache.catalina.core.ContainerBase.[jboss.web].[localhost].[TestFileUpload].[FileUploadServlet]] Servlet.service() for servlet FileUploadServlet threw exception
java.lang.UnsupportedClassVersionError: Bad version number in .class file
     at java.lang.ClassLoader.defineClass1(Native Method)
     at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
     at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:124)
     at org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:1817)
     at org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:872)
     at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1325)
     at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1204)
     at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)
     at org.apache.commons.fileupload.disk.DiskFileItemFactory.createItem(DiskFileItemFactory.java:199)
     at org.apache.commons.fileupload.FileUploadBase.parseRequest(FileUploadBase.java:361)
     at org.apache.commons.fileupload.servlet.ServletFileUpload.parseRequest(ServletFileUpload.java:126)
     at com.abc.servlet.FileUploadServlet.doPost(FileUploadServlet.java:59)
     at javax.servlet.http.HttpServlet.service(HttpServlet.java:710)
     at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
     at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
     at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
     at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)
     at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
     at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
     at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)
     at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
     at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:179)
     at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:84)
     at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
     at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
     at org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:156)
     at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
     at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:241)
     at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
     at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:580)
     at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
     at java.lang.Thread.run(Thread.java:595)
What could be the reason?
This is the servlet:
package com.abc.servlet;
import java.io.IOException;
import java.io.InputStream;
import java.util.Iterator;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileItemFactory;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
* Servlet implementation class FileUploadServlet
public class FileUploadServlet extends HttpServlet {
     private static final long serialVersionUID = 1L;
     * @see HttpServlet#HttpServlet()
    public FileUploadServlet() {
        super();
        // TODO Auto-generated constructor stub
      * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
          // TODO Auto-generated method stub
      * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
          boolean isMultiPart = false;
          try {
               // Check that we have a file upload request
               isMultiPart = ServletFileUpload.isMultipartContent(request);
               System.out.println("isMultiPart=" + isMultiPart);
               if (isMultiPart) {
                    // Create a factory for disk-based file items
                    FileItemFactory fileItemFactory = new DiskFileItemFactory();
                    // Create a new file upload handler
                    ServletFileUpload servletFileUpload = new ServletFileUpload(fileItemFactory);
                    List fileItemsList = servletFileUpload.parseRequest(request);
                    FileItem fileItem = null;
                    String fileName = null;
                    InputStream inputStream = null;
                    long inputStreamSize = -1;
                    Iterator iter = fileItemsList.iterator();
                    while (iter != null && iter.hasNext()) {
                         FileItem fileItem1 = (FileItem) iter.next();
                         System.out.println("---fileItem1.isFormField()=" + fileItem1.isFormField());
                         if (fileItem1.isFormField()) {
                              String fieldName = fileItem1.getFieldName();
                              String fieldValue = fileItem1.getString();
                              System.out.println("fieldName=" + fieldName);
                              System.out.println("fieldValue=" + fieldValue);
                         } else {
                              fileItem = fileItem1;
                    fileName = fileItem.getName();
                    inputStream = fileItem.getInputStream();
                    inputStreamSize = fileItem.getSize();
                    System.out.println("fileName=" + fileName);
                    System.out.println("inputStream=" + inputStream);
                    System.out.println("inputStreamSize=" + inputStreamSize);
                    inputStream.close();
                    System.out.println("inputStream closed");
          } catch (FileUploadException e) {
               // TODO Auto-generated catch block
               e.printStackTrace();
}Edited by: srhcan on Jun 19, 2012 8:04 PM