URGENT : Multiple Attachments using JavaMail

Question

Hello ,
I'm trying to send multiple attachments to a single mailid. I have 3 text boxes in my JSP page which holds the file name that is selected . in the next page i retrieving the values of those filenames and sending it as attachment .
But when i do so , i'm getting NullPointeException when one of 2 file is choose . but when i choose 3 files to send , it is working fine . Can any one help pls,
Here is the code
public class Attachservlet extends HttpServlet{
     public void doPost(HttpServletRequest req,HttpServletResponse res) throws ServletException,IOException{
     String host="172.30.1.35";
     String full[]=new String[3];
     String part[]=new String[3];
     String fname[]=new String[3];
     String pname[]=new String[3];
     String ss[]=new String[3];
     String name[]=new String[3],conc="";
     int j,jj;
     String sender_email=req.getParameter("senderemail");
     String sender_name=req.getParameter("sendername");
     String receiver_email=req.getParameter("receiveremail");
     String receiver_name=req.getParameter("receivername");
     String sent_message=req.getParameter("area");
     PrintWriter out=res.getWriter();
     Properties props=System.getProperties();
     props.put("mail.smtp.host",host);
     Session session=Session.getDefaultInstance(props,null);
     MimeMessage message=new MimeMessage(session);
     try{
     for ( jj=0;jj<3;jj++){
     j=jj+1;
     name[jj]="filename"+j;
     pname[jj]="pname"+j;
     ss[jj]=req.getParameter(name[jj]);
     part[jj]=req.getParameter(pname[jj]);
     if(ss[jj].length()!=0){
     System.out.println("values is "+ss[jj] +"\n"+part[jj]);
     System.out.println("values is "+ss[jj] +"\n"+part[jj]);
     conc=conc+ss[jj]+",";
     System.out.println(conc);     
     message.setFrom(new InternetAddress(sender_email,"Sumathi"));
     message.addRecipient(Message.RecipientType.TO,new InternetAddress(receiver_email));
     message.setSubject(receiver_name);
     BodyPart bodypart=new MimeBodyPart();
     bodypart.setText(sent_message);
     Multipart multi=new MimeMultipart();
     multi.addBodyPart(bodypart);
     bodypart = new MimeBodyPart();
     DataSource source=new FileDataSource("test.jsp");
     bodypart.setDataHandler(new DataHandler(source));
     bodypart.setFileName(part[jj]);
     multi.addBodyPart(bodypart);
     message.setContent(multi);
     Transport.send(message);
     res.sendRedirect("http://sumathi/Mail/Success.jsp");
     System.out.println("Message Sent");
     }catch(Exception e){
     System.err.println("An Exception has Arrised \t"+e);
     public void doGet(HttpServletRequest req,HttpServletResponse res)throws ServletException,IOException{
     doPost(req,res);
Any Help pls ,
Thanks in Advance !

Answer 1

OK,
Although you didn't post the stack trace from your NullPointer, my guess is that it's being thrown at this line:
if(ss[jj].length()!=0){
your ss[jj] variable is being assigned the value: req.getParameter(name[jj]); This value is null in the case when you have anything less that 3 parameters in your form.
You need to check for a null value at this point.