import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class SendRedirectServlet extends HttpServlet{
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		response.setContentType("text/html");
		PrintWriter pw = response.getWriter();
		String name = request.getParameter("username");
		String password = request.getParameter("password");
		if(name.equals("James")&& password.equals("abc")){
			response.sendRedirect("/SendRedirect/ValidUserServlet");
		}
		else{
			pw.println("u r not a valid user");
		}
	}
}

 ValidUserServlet.java 

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class ValidUserServlet extends HttpServlet{
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
	PrintWriter pw = response.getWriter();
	pw.println("Welcome to roseindia.net " + " ");
	pw.println("how are you");
}
}