UNIT III – Java Servlets, XML & AJAX Notes
1. Java Servlets
Servlet Architecture Overview
Servlet is a Java program that runs on a web server and is used to create dynamic web pages.
Flow: Client → Server → Servlet → Response
Hello World Servlet
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class HelloServlet extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse res)
throws IOException {
res.setContentType("text/html");
PrintWriter out = res.getWriter();
out.println("<h1>Hello World</h1>");
}
}
Servlet Life Cycle
init() → service() → destroy()
Session Tracking
Methods: Cookies, HttpSession, URL Rewriting
Database Connectivity (MySQL)
Connection con = DriverManager.getConnection(
"jdbc:mysql://localhost:3306/db", "root", "1234");
2. XML
XML Example
<student>
<name>Aditya</name>
1. Java Servlets
Servlet Architecture Overview
Servlet is a Java program that runs on a web server and is used to create dynamic web pages.
Flow: Client → Server → Servlet → Response
Hello World Servlet
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class HelloServlet extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse res)
throws IOException {
res.setContentType("text/html");
PrintWriter out = res.getWriter();
out.println("<h1>Hello World</h1>");
}
}
Servlet Life Cycle
init() → service() → destroy()
Session Tracking
Methods: Cookies, HttpSession, URL Rewriting
Database Connectivity (MySQL)
Connection con = DriverManager.getConnection(
"jdbc:mysql://localhost:3306/db", "root", "1234");
2. XML
XML Example
<student>
<name>Aditya</name>
