Servlet的request在服务器实现内部跳转

标签：方式   object   getattr   请求转发   访问   pos   attr   void   system   

请求转发：
一种在服务器内部的资源跳转方式
1. 步骤：
1. 通过request对象获取请求转发器对象：RequestDispatcher getRequestDispatcher(String path)
2. 使用RequestDispatcher对象来进行转发：forward(ServletRequest request, ServletResponse response)
2. 特点：
1. 浏览器地址栏路径不发生变化
2. 只能转发到当前服务器内部资源中。
3. 转发是一次请求

共享数据：
* 域对象：一个有作用范围的对象，可以在范围内共享数据
* request域：代表一次请求的范围，一般用于请求转发的多个资源中共享数据
* 方法：
1. void setAttribute(String name,Object obj):存储数据
2. Object getAttitude(String name):通过键获取值
3. void removeAttribute(String name):通过键移除键值对

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("/requestDemo5")
public class RequestDemo5 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        System.out.println("demo5被访问了...");
        //服务器内部跳转到demo6
        //request作用域存储变量
        request.setAttribute("name","chris");
        request.getRequestDispatcher("/requestDemo6").forward(request,response);
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request,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("/requestDemo6")
public class RequestDemo6 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doGet(request,response);
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        System.out.println("demo6被访问了。。。");
        Object name = request.getAttribute("name");
        System.out.println(name);
    }
}

Servlet的request在服务器实现内部跳转

标签：方式   object   getattr   请求转发   访问   pos   attr   void   system   

原文地址：https://www.cnblogs.com/codegzy/p/14743095.html