Response-重定向-代码实现
案例:
1. 完成重定向
重定向:资源跳转的方式
代码实现:
设置状态码为302
response.setStatus(302);
设置响应头location
response.setHeader("location","/day15/responseDemo2");
简单的重定向方法
response.sendRedirect("/day15/responseDemo2");
package com.example.day_14_response; 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; /** * 重定向 */ @WebServlet("/responseDemo1") public class ResponseDemo1 extends HttpServlet { protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { System.out.println("demo1........"); //访问/responseDemo1,会自动跳转到/responseDemo2资源 /* //1. 设置状态码为302 response.setStatus(302); //2.设置响应头location response.setHeader("location","/day15/responseDemo2");*/ request.setAttribute("msg","response"); //动态获取虚拟目录 String contextPath = request.getContextPath(); //简单的重定向方法 response.sendRedirect(contextPath+"/responseDemo2"); //response.sendRedirect("http://www.itcast.cn"); } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { this.doPost(request,response); } }
package com.example.day_14_response; 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("/responseDemo2") public class ResponseDemo2 extends HttpServlet { protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { System.out.println("demo2222222........"); Object msg = request.getAttribute("msg"); System.out.println(msg); } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { this.doPost(request,response); } }
Response-重定向-特点
重定向的特点:redirect
1. 地址栏发生变化
2. 重定向可以访问其他站点(服务器)的资源
3. 重定向是两次请求。不能使用request对象来共享数据
转发的特点:forward
1. 转发地址栏路径不变
2. 转发只能访问当前服务器下的资源
3. 转发是一次请求,可以使用request对象来共享数据