Solved

JSP Empty String Problem

Posted on 2002-04-08
3
244 Views
Last Modified: 2006-11-17
hi,

I have two edits on my first jsp page, which values I send via form submit to the second page.

I want to test on my second page whether these values is empty, and if they are, forward to another page.

The problem is that when the values are empty, the jsp engine regards them as "not empty"?? and doesnt go into the fowarding
if statement.

I have even tested the values by displaying them in the second page, but no luck.

If I go and set these values to "" before i execute the if, it works!

I must be missing something obvious.

--page 1--

<input type="text" name="edtItemNumber">
 <input type="text" name="edtStoreLocation">


--page 2--

String item = request.getParameter("edtItemNumber");
String location = request.getParameter("edtStoreLocation");

if ((item == "") || (location == ""))
{application.getRequestDispatcher("/oraerror.jsp?ErrorStr=Please complete Item number and Store Location." ).forward(request,response);}


Please help.
0
Comment
Question by:barnarp
  • 2
3 Comments
 
LVL 92

Accepted Solution

by:
objects earned 75 total points
ID: 6927302
You shouldn't use == to test String equality. It tests for object equality, not whether the two objects represent the same string. To test if a string is empty use one of the following:

item.equals("")

or

item.length()==0

0
 

Author Comment

by:barnarp
ID: 6927313
Thanks alot.

Do you know of any reference on the net, where I can learn more about string functions etc ?

Pierre
0
 
LVL 92

Expert Comment

by:objects
ID: 6927338
Pierre,

Try:
http://java.sun.com/docs/books/tutorial/java/data/strings.html

And of course the good old javadoc :-)

http://www.objects.com.au
Brainbench MVP for Java 1
http://www.brainbench.com
0

Featured Post

Announcing the Most Valuable Experts of 2016

MVEs are more concerned with the satisfaction of those they help than with the considerable points they can earn. They are the types of people you feel privileged to call colleagues. Join us in honoring this amazing group of Experts.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
Apps blocked by Java 9 88
table example 4 32
type mismatch (Object[] to double[] 4 33
Html Table Looping (part 2) 5 27
By the end of 1980s, object oriented programming using languages like C++, Simula69 and ObjectPascal gained momentum. It looked like programmers finally found the perfect language. C++ successfully combined the object oriented principles of Simula w…
Introduction Java can be integrated with native programs using an interface called JNI(Java Native Interface). Native programs are programs which can directly run on the processor. JNI is simply a naming and calling convention so that the JVM (Java…
Viewers learn how to read error messages and identify possible mistakes that could cause hours of frustration. Coding is as much about debugging your code as it is about writing it. Define Error Message: Line Numbers: Type of Error: Break Down…
This tutorial covers a practical example of lazy loading technique and early loading technique in a Singleton Design Pattern.

856 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question