Jsp Scripting Element: These are the element which insert java code into generated servlet. Thses gets evaluated at run time and displayed on page.
Types:
Expression: It is used to insert java values directly into the output. On translation it goes to out.print statement.
e.g:
<%=request.getX() >
Points to remember:
1) You can't use semicolon to end an expression.
2) Expression evaluated left to right.
3) It can contain any expression that is valid as per java language.
Scriptlet: It is used to insert java code in -jspService method of generated servlet.
e.g:
<% if(condition){ %>
<b>True</b>
<% else %>
<b>false</b>
Declaration: It is used to insert declaration of fields or method defination in servlet class.
e.g:
<%! Integer i =10; %>
or
<%! public void a(){
}
%>
It can be used to override jspInt and jspDestroy methods.