2021-10-21请求转发与重定向的区别

package com.example.servlet;

import sun.util.resources.cldr.ml.CalendarData_ml_IN;

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.io.PrintWriter;


@WebServlet("/s5")
public class Servlet05 extends HttpServlet {
    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println("Servlet05.....");
        //接收参数
        System.out.println("姓名" + req.getParameter("name"));

        //设置作用域
        req.setAttribute("admin", "admin");

        //重定向跳转到首页
        resp.sendRedirect("index.jsp");


    }
}

package com.example.servlet;

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;


@WebServlet("/s6")
public class Servlet06 extends HttpServlet {
    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println("Servlet06.....");
        //接收参数
        System.out.println("姓名" + req.getParameter("name"));


        //设置作用域
        req.setAttribute("admin", "admin");


        //重定向跳转到首页
//        resp.sendRedirect("index.jsp");
        //请求转发
//        req.getRequestDispatcher("index.jsp").forward(req, resp);


        //跳转到百度

        resp.sendRedirect("https://www.baidu.com");
        //请求转发
//        req.getRequestDispatcher("index.jsp").forward(req, resp);

    }
}

•  1.请求转发地址栏不改变，而重定向改变
  

•  2.请求转发是服务端跳转，而重定向是客户端
  

•  3.请求转发只有一次转发，而重定向是两次
  

•  4.请求转发的request作用域可以共享，而重定向不共享
  

•  5.请求转发只可以跳转到当前项目资源，而重定向可以跳转到任意资源