Question

I want to check if a specific item is selected in a drop-down menu. Suppose I have something like this in my JSP:

<sf:select path="xItem" >
    <sf:option value="val1" />
    <sf:option value="val2" />
</sf:select>

and in my corresponding java bean, I want to check it as

if (xItem.equals("val1")) xItem = doSomething();

but, if I define “val1” as a constant, i.e., final static String mytext="val1", and change my jsp file as <sf:option value="${MyClass.mytext}" />, Spring will complain that mytext is not a property of MyClass.
Is there anyway to define this text as a constant and refer to it in JSP and the corresponding Java class?

Answer 1

The ${MyClass.mytext} expression applies to beans and properties, specifically it means that the server is expecting to find a bean saved in the current context as MyClass and on that bean to call a getter called getMyText (it’s a jspContext.FindAttribute) which isn’t the case here since you have a static member on a class.

Here are some workarounds off the top of my head:

• use a scriptlet and refer to the static member (if you can live with having scriptlets inside your JSPs);
• save the value in your controller under some key inside your model and refer it in your JSP by that key;
• define a custom tag that given a class name and static member invokes it and places it under some key in page scope and you can use if from there (see an example in this article: Scriptless JSP Pages: The Constant Constants Consternation);
• define an EL function that returns the value of the constant (see an example in the same article Scriptless JSP Pages: The Constant Constants Consternation, scroll to the end of it).

I would personally go with defining an EL function if you refer to constants often in your JSPs or set it under some model key in the controller if it’s a one time only use.