JSP (6)--jsp declaration

JS in the JSP you are writing to become a class definition. All the scriptlets you write will be placed into one of the methods of this class. Again, you can add variables and methods to declare them in this class. Of course, you can also use these variables and methods from scriptlets and expressions.

In order to add a statement, you must use the <%! and%> to circle your statement, such as:

＜%@ page import="java.util.*" %＞

＜HTML＞

＜BODY＞

＜%!

Date theDate = new Date();

Date getDate()

{

System.out.println( "In getDate() method" );

return theDate;

}

%＞

Hello! The time is now ＜%= getDate() %＞

＜/BODY＞

＜/HTML＞

The above example has declared variables and methods: A Date variable thedate and a method getdate. These two are valid from now on in both scriptlets and expressions, because they are already defined.

Unfortunately, the above example does not work: No matter how you overload the page, the date is the same. The reason for these statements is that they are only counted once when the Web page is loaded. It's like we create a class in Visual C + + and define the initialization value of the variable.

The practice in this tutorial is to modify the example above and add another function computedate to reinitialize the thedate. and add a scriptlet to call computedate each time.