Evaluate empty or null JSTL c tags

You can use the  or  for this.

 test="${empty var1}">
    var1 is empty or null.

 test="${not empty var1}">
    var1 is NOT empty or null.

or

     test="${empty var1}">
        var1 is empty or null.
    
    
        var1 is NOT empty or null.
    

The ${not empty var1} can also be done by ${!empty var1}.

To learn more about those ${} things (the Expression Language, which is a separate subject from JSTL),check here.

http://stackoverflow.com/questions/2811626/evaluate-empty-or-null-jstl-c-tags