Head First Servlets and JSP, 2nd Edition

Chapter 8. Scriptless JSP: Script-free pages

Do your web page designers really have to know Java? Is that fair? Do they expect server-side Java programmers to be, say, graphic designers? And even if it’s just you on the team, do you really want a pile of bits and pieces of Java code in your JSPs? Can you say, “maintenance nightmare”? Writing scriptless pages is not just possible, it’s become much easier and more flexible with the new JSP 2.0 spec, thanks to the new Expression Language (EL). Patterned after JavaScript and XPath, web designers feel right at home with EL, and you’ll like it too (once you get used to it). But there are some traps... EL looks like Java, but isn’t. Sometimes EL behaves differently than if you used the same syntax in Java, so pay attention!

OBJECTIVES

Building JSP pages using the Expression Language (EL) and Standard Actions

7.1	Write a code snippet using top-level variables in the EL. This includes the following implicit variables: pageScope, requestScope, sessionScope, and applicationScope; param and paramValues; header and headerValues; cookies; and initParam.
7.2	Write a code snippet using the following EL operators: property access (the . operator), collection access (the [] operator).
7.3	Write a code snippet using the following EL operators: aritmetic operators, relational operators, and logical operators.
7.4	For EL functions: Write a code snippet using an ...