CODEWITHSUNDEEP
javajspnullpointerexception
Wistak
Wistak

Reputation: 51

Null Exception using JSP

I'm trying to make a program in NetBeans... It's supposed to be a Salad menu, everything is working fine unless I don't select any value... The error is this:

type Exception report

messageInternal Server Error

descriptionThe server encountered an internal error that prevented it from fulfilling this request.

exception

org.apache.jasper.JasperException: java.lang.NullPointerException

root cause java.lang.NullPointerException note The full stack traces of the exception and its root causes are available in the GlassFish Server Open Source Edition 4.1 logs.

Here's my JSP code: 

  <%
   String  prueba [] = request.getParameterValues("ingredientes");
   out.println("<h1>RESULTADO DE TU ENSALADA!!</h1>");
   out.println("<br><br><b>Tu ensalada tiene:</b><br>");
   for (int o = 0; o < prueba.length; o++){
       out.println(prueba [o]+"<br>");

   String  prueba2 [] = request.getParameterValues("adicionales");
   out.println("<br><br><b> Adicional tiene:</b><br>");
   for (int o = 0; o < prueba2.length; o++){
       out.println(prueba2 [o]+"<br>");

   String  prueba3 [] = request.getParameterValues("aderezos");
   out.println("<br><br><b> Con el aderezo:<br></b>");
   for (int o = 0; o < prueba3.length; o++){
       out.println(prueba3 [o]+"<br>");       

   %>

I know I'm missing some "}" but deleted them to keep the Code format. Already tried using "catch" but doesn't seem to work or maybe did it wrong. Any suggestions?

EDIT:

OK guys, so I just found a solution to my problem, I don't know why I didn't think of this earlier. Thanks for your quick answers.

This was my solution:

       if (request.getParameterValues("ingredientes") != null){
   String  prueba [] = request.getParameterValues("ingredientes");
   out.println("<h1>RESULTADO DE TU ENSALADA!!</h1>");
   out.println("<br><br><b>Tu ensalada tiene:</b><br>");
   for (int o = 0; o < prueba.length; o++){
   out.println(prueba [o]+"<br>"); }
       }else{
           out.println("Selecciona UNO O MAS Ingrediente Porfavor!");
       }

I just added this condition:

if (request.getParameterValues("ingredientes") != null)

Upvotes: 0

Views: 844

Answers (1)

Will
Will

Reputation: 6711

At a guess I'd say that one of these is returning null.

String  prueba [] = request.getParameterValues("ingredientes");
String  prueba2 [] = request.getParameterValues("adicionales");
String  prueba3 [] = request.getParameterValues("aderezos");

Then if you try to call

prueba.length, and prueba is null, you will get a NullPointerException

Upvotes: 1

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