007.servlet中如何跳转到另一个servlet中？（转发和重定向的区别和使用）

 

 

 

 

 

 

package com.ll.homework;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Date;

@WebServlet("/servlet4")
public class ServletHomeDemo04 extends HttpServlet
{
    /**
     * 问题：servlet中如何跳转到另一个servlet中？利用转发
     * 4.实现重定向以后，其后的代码不在执行
     */
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException
    {
        RequestDispatcher requestDispatcher = req.getRequestDispatcher("/servlet3");//得到转发器
        requestDispatcher.forward(req,resp);//实现转发 格式：转发器对象..forward(req,resp)
    }
}

 

 

 

 

 

 

 

 

 

package com.ll.homework;

import javax.servlet.*;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Date;

@WebServlet("/servlet3")
public class ServletHomeDemo03 extends HttpServlet
{
    /**
     * 问题：servlet中如何跳转到另一个servlet中？利用重定向
     * 2.实现重定向
     * 3.举例：response.sendRedirect("loginServlet");
     * 4.实现重定向以后，其后的代码不在执行
     */
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException
    {
        System.out.println("当前的时间是："+new Date());
        resp.sendRedirect("servlet4");
    }

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException
    {
        doPost(req, resp);
    }
}