Java Enterprise Best Practices

Avoid Using Scripting Elements

Whether you use JSP pages for only the View portion of the application or for other roles as well, avoiding scripting elements (i.e., raw Java code in the pages) is always a good idea. Using scripting elements exposes you to, at least, the following problems:

• Syntax errors are very easy to make and extremely hard to locate because the scripting element code is interleaved with the code generated by the container.

• Scripting code can be reused only through copy/paste.

• To a nonprogrammer charged with maintaining the look-and-feel aspects of the pages, scripting code is very distracting and easy to corrupt by mistake. Some web page authoring tools used by this group of people also remove or corrupt scripting elements.

Before the introduction of custom tag libraries in JSP 1.1, scripting elements were your only choice. Even in the latest JSP version, scripting elements are still supported (because Java specifications go to great lengths to be backward-compatible). But with the introduction of custom tag libraries, and especially the libraries defined by the JSTL specification, there’s really no good reason to use scripting elements anymore.