Working with Scripting Tags :
JSP Scripting Tags allow a java programmer to
add a script code into the java code of a JSP. In most of the cases java is the
scripting language used to build a JSP page. There are many types of scripting
tag:
Types of Scripting Tags:
There are mainly three JSP scripting tags:
- The Scriptlet Tag: This tag allow you
to declare variables, that you can use later in JSP page. It is also allow you
to write the script code for implementing the _jspService method. 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:
<%
script code
%>
Example:
<html>
<body>
<%
for (int i=0; i<10;i++)
{
out.println(i);
}
%>
</body>
</html>
The Declarative Tag: This tag allows you to declare instance and class variable and implement class methods such as jspInit and jspDestroy. JSP declaration is used to declare variables and methods in a page's scripting language.
The syntax for a declaration is as follows:
<%!
script code
%>
Example:
<%!
int i, j;
int fun (int i)
{
return i;}
%>
<%i=1;>
<%j=fun (i);%>
<%out.println(j);%>
The Expression Tag: Through this tag we show the resultant value. The expression tag places in the out. print method during the translation stage of the JSP lifecycle.
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:
<%=
script code
%>
Example:
<%! int count; %>
<html> <body>
<% count++ %>
This page is requested by <%=count%> number of users till now.
</body>
</html>
Example of Scripting tags:
<%@page import="java.util.*" language="java" %>
<html>
<body bgcolor="pink">
<center><h1>Using Scripting Elements</h1></center>
<%! int count,a,b;
int fun (int a)
{
return 10*a;
}%>
<% a=1;
count++;
for (int i=0;i<5;i++)
{
out.println("value of i in iteration no.<br/>");
}
b=fun(a);
out.println("value of b");
%>
This page is requested by <b><%=count%></b>number of times on date
<b><%=new Date()%>
</b>
</body>
</html>
Running the application on the server:
Run the tomcat server then write the below line in the URL
http://localhost:8080/JSP/
Here JSP is the Context path, which we mentioned in the server.xml file, which
is present in (E:\Program Files\Apache Software Foundation\Tomcat 6.0\conf)
directory.
After giving the URL a set a listing will come, here only one appears
As index.JSP,click it
http://localhost:8080/JSP/index.JSP
OUTPUT:
