Understanding JSP
CASE 1: Try to create method inside <% ,.... %>
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<h1>Hello</h1>
<%!public int sum(int a, int b) {
return a + b;
}%>
Value of sum of 67 and 89 is
<%=sum(67, 89)%>
<br>
<%
public int sum1(int a, int b) {
}
return a + b;
int i = 3;
int j = 8;
int k = i + j;
out.println("Value of k is " + k);
%>
<br>
<%
int l = 3;
int m = 12;
int n = l + m;
%>
Value of n is
<%=n%>
</body>
</html>
We cannot use methods inside <%%>
CASE 2: We can add html code between the JSP scriplets.
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
Simple for loop
<br>
<% for(int i = 0; i<5; i++) { %>
<br>
Value of i is = <%=i %>
<%} %>
</body>
</html>
Behind the scene :
JSP is converted to a class so this test.jsp is converted to a java class
Java class is basically a servlet
Every jsp is a servlet
When we run it on server (tomcat) , tomcat converts jsp to servlet
Default is get method , Every <%...%> is converted added to doGet method of the servlet class is generated from JSP.
All the HTML code will be put into out.write() by tomcat
Thats why method declared inside <%..%> gives the compilation as we cannot define a method inside a method for that we need : <%!..%>
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