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Chapter 10 JSP Scripting Elements

Template Text

In many cases, a large percentage of your JSP page just consists of static

HTML, known as template text. In almost all respects, this HTML looks just

like normal HTML, follows all the same syntax rules, and is simply  passed

through  to the client by the servlet created to handle the page. Not only

does the HTML look normal, it can be created by whatever tools you already

are using for building Web pages. For example, I used Allaire's HomeSite for

most of the JSP pages in this book. 

There are two minor exceptions to the  template text is passed straight

through  rule. First, if you want to have 

<%

 in the output, you need to put 

<\%

in the template text. Second, if you want a comment to appear in the JSP

page but not in the resultant document, use

<%   JSP Comment   %>

HTML comments of the form 

are passed through to the resultant HTML normally. 

10.2 JSP Expressions

A JSP expression is used to insert values directly into the output. It has the

following form: 

<%= Java Expression %>

The expression is evaluated, converted to a string, and inserted in the

page. This evaluation is performed at run time (when the page is requested)

and thus has full access to information about the request. For example, the

following shows the date/time that the page was requested: 

Current time: <%= new java.util.Date() %>

Predefined Variables

To simplify these expressions, you can use a number of predefined variables.

These implicit objects are discussed in more detail in Section 10.5, but for

the purpose of expressions, the most important ones are: 

request

, the 

HttpServletRequest

response

, the 

HttpServletResponse

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