request域对象和请求转发

 

request的其他功能

request是一个域对象

request对象也是一个存储数据的区域对象，所以也具有如下方法：

setAttribute(String name, Object o)

getAttribute(String name)

removeAttribute(String name)

注意：request域的作用范围：一次请求中

request完成请求转发

获得请求转发器----path是转发的地址

RequestDispatcher getRequestDispatcher(String path)

通过转发器对象转发

requestDispathcer.forward(ServletRequest request, ServletResponse response)

package com.content.forward;

import java.io.IOException;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class Servlet1 extends HttpServlet {

	protected void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		
		//想request域中存储数据
		request.setAttribute("name", "tom");
		
		
		//servlet1 将请求转发给servlet2
		RequestDispatcher dispatcher = request.getRequestDispatcher("/servlet2");
		//执行转发的方法
		dispatcher.forward(request, response);
		
	}

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

package com.content.forward;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class Servlet2 extends HttpServlet {

	protected void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		
		//从request域中取出数据
		Object attribute = request.getAttribute("name");
		
		response.getWriter().write("hello haohao..."+attribute);
	}

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