JSP Scriptlets

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JSP Scriptlets

<%!

public void jspDestroy() {

bookDBAO = null;

}

JSP Scriptlets

A JSP scriptlet is used to contain any code fragment that is valid for the scripting language used
in a page. The syntax for a scriptlet is as follows:

scripting-language-statements

When the scripting language is set to java, a scriptlet is transformed into a Java programming
language statement fragment and is inserted into the service method of the JSP page's servlet. A
programming language variable created within a scriptlet is accessible from anywhere within
the JSP page.

In the web service version of the hello1 application, greeting.jsp contains a scriptlet to
retrieve the request parameter named username and test whether it is empty. If the if statement
evaluates to true, the response page is included. Because the if statement opens a block, the
HTML markup would be followed by a scriptlet that closes the block.

String username = request.getParameter(

"username");

if ( username != null && username.length() > 0 ) {

<%@include file=

"response.jsp" %>

}

JSP Expressions

A JSP expression is used to insert the value of a scripting language expression, converted into a
string, into the data stream returned to the client. When the scripting language is the Java
programming language, an expression is transformed into a statement that converts the value
of the expression into a String object and inserts it into the implicit out object.

The syntax for an expression is as follows:

<%=

scripting-language-expression %>

JSP Expressions

Chapter 9 · Scripting in JSP Pages

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