案例-重定向

案例-重定向

重定向：资源跳转的方式

图解

 

 java代码

ResponseDemo01

@WebServlet("/ResponseDemo01")
public class ResponseDemo01 extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println("ResponseDemo01....");
        //访问/responseDemo01 会自动跳转到/ResponseDemo02资源
        //1.设置状态码为302
        resp.setStatus(302);
        //2.设置响应头location
        resp.setHeader("location","/ResponseDemo02");
    }

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

ResponseDemo02

@WebServlet("/ResponseDemo02")
public class ResponseDemo02 extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println("ResponseDemo02....");
    }

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

运行结果

重定向（redirect）的特点

1. 地址栏发送变化
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(forward)的特点：

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