Boolean Object in JSTL

[Chris Cornelius]

Hello,

I am a JSP, JSTL newbie and have really enjoyed
this forum!!

My question is I need to evaluate a Boolean object,
is there a way to do this?

This is what I thought would work and no dice:
<c:when test="${item.locked == 'true'}">

Thanks in advance for your help!

[Bear Bibeault]

By enclosing the true in quotes, you've made a string out of it.

Rather, you can just use:

<c:when test="${item.locked}"> 

or

<c:when test="${item.locked == true}"> 

but the latter is unecessarily verbose.
[ August 02, 2005: Message edited by: Bear Bibeault ]

[Chris Cornelius]

Thanks for the tip, I ran the program and got this:

WARNING: CORE3283: stderr: javax.servlet.jsp.JspTagException: javax.servlet.jsp.JspException: An error occurred while evaluating custom action attribute "test"
with value "${item.locked}": Unable to find a value for "locked" in object.

When debugging the program I can see the Boolean value in the bean object.

What else could I be doing wrong?

Thanks again!!

[Bear Bibeault]

What is the signature for the property accessor for 'locked'?

It should be:

public boolean getLocked()

[Chris Cornelius]

This is the bean method:

public Boolean isLocked()
{
return locked;
}

[Bear Bibeault]

I'm not sure if the EL evaluation is sensitive to the 'is' form of a boolean accessor. Try the 'get' signature and see if your life improves.

[Chris Cornelius]

Thank you very much for your help!!

I went ahead and changed everything from
Boolean to boolean and the method to getLocked,
and it worked like a charm!

Chris

[Bear Bibeault]

I'm glad it's working for you now.

After doing some testing, what's weird is that apparently it was the return type of Boolean (rather than boolean) in conjunction with the is/get prefix for the accessor method that was tripping you up.

The following formats work as one would expect:

 
boolean isLocked() { return true; }
boolean getLocked() { return true; }
Boolean getLocked() { return Boolean.TRUE; }
 

but this

 
Boolean isLocked() { return Boolean.TRUE; }
 

generates the "Unable to find a value" error (at least under Tomcat -- Resin 3 returns a blank rather than throwing an error).

I'm not as familiar with the JavaBeans Specification as I am with the Servlets, JSP and JSTL specs, so I'm not sure exactly what precept the latter form violates.

I'm intrigued enough to investigate further...

[Adeel Ansari]

Thanks Bear for your efforts.

May be is works only with primitive boolean and get works with any. Just a thought.
[ August 04, 2005: Message edited by: Adeel Ansari ]

[Chris Cornelius]

Thanks for the useful info, I will definately use that
in future projects.