An application server converts JSP (JavaServer Pages) pages into Java servlets for execution.
How it works:
- When a user requests a JSP page, the application server receives the request.
- The server checks if a servlet for that JSP page already exists in memory.
- If not, the server compiles the JSP page into a Java servlet based on the JSP specification.
- This generated servlet contains the Java code that handles the logic and dynamic content of the JSP page.
- The server then executes the generated servlet, producing the final HTML output that is sent back to the user's browser.
Benefits of this conversion:
- Improved performance: By compiling JSP pages into servlets, the application server can execute them more efficiently.
- Increased security: The generated servlet code is typically compiled and executed in a secure environment.
- Simplified development: JSP pages provide a more user-friendly way to create dynamic web content compared to writing raw Java code.
Example:
Let's say you have a JSP page called welcome.jsp
with the following code:
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Welcome</title>
</head>
<body>
<h1>Welcome to my website!</h1>
</body>
</html>
The application server will convert this JSP page into a servlet class, which will contain the necessary Java code to generate the HTML output shown in the browser.