Request请求转发和Request_共享数据(域对象)

Request请求转发

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

RequestD8 ：

@WebServlet("/requestD8")
public class RequestD8 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        System.out.println("request8被访问....");
        //转发到request9
        request.getRequestDispatcher("/requestD9").forward(request,response);
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request, response);
    }
}

RequestD9：

@WebServlet("/requestD9")
public class RequestD9 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        System.out.println("request9被访问....");

    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request, response);
    }
}