Head First Servlets and JSP, 2nd Edition

Sneak peek at EL

The entire next chapter is on EL, so we won’t go into details here. The only reason we’re covering it is because it’s yet another kind of element (with its own syntax) that goes in a JSP, and the exam objectives for this chapter include recognizing everything that can go into a JSP.

Note

An EL expression ALWAYS looks like this: ${something}

In other words, the expression is ALWAYS enclosed in curly braces, and prefixed with a dollar ($) sign.

This EL expression:

Please contact: ${applicationScope.mail}

Is the same as this Java expression:

Please contact: <%= application.getAttribute("mail") %>

There are no Dumb Questions

Q:

Q: Not to be all negative, but I’m not sure I see an earth-shattering difference between the EL and the Java expression. Sure, it’s a little shorter, but is that worth a whole new scripting language and JSP coding approach?

A:

A: You SO haven’t seen the full benefit of EL yet. The differences will become obvious in the next chapter when we dive in. But you must remember that to a Java programmer, EL is NOT neccessarily a dramatic development advantage. In fact, to a Java programmer it simply means “one more thing (with its own syntax and everything) to learn, when, hey, I already KNOW Java...” But it’s not always about you. EL is much easier for a non-Java programmer to learn and get up to speed in. And for a Java programmer, it is still much easier to maintain a scriptless page. Yes, it’s still something to learn. It doesn’t let web page designers completely ...