我不知道咋运用了。顺便请老师给个正确的方法

来源：2-6 自由编程

dobe001

2019-08-10 11:29:41

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
    <form action="/direct/rs">
        <input type="text" name="num" placeholder="请输入100以内的数字">
        <input type="submit" value="求累加和">
    </form>
</body>
</html>

package com.ccc.direct;

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

/**
 * Servlet implementation class RequestServlet
 */
@WebServlet("/direct/rs")
public class RequestServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;

	/**
	 * @see HttpServlet#HttpServlet()
	 */
	public RequestServlet() {
		super();
		// TODO Auto-generated constructor stub
	}

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse
	 *      response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		// TODO Auto-generated method stub
		String num=request.getParameter("num");
		int n=Integer.parseInt(num);
		int sum=0;
		for(int i=0;i<=n;i++) {
			sum+=i;
		}
		request.setAttribute("result", sum);
		request.getRequestDispatcher("/direct/rs1").forward(request, response);;
	}

}

package com.ccc.direct;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class ReponseServlet
 */
@WebServlet("/direct/rs1")
public class ResponseServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;

	/**
	 * @see HttpServlet#HttpServlet()
	 */
	public ResponseServlet() {
		super();
		// TODO Auto-generated constructor stub
	}

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse
	 *      response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		// TODO Auto-generated method stub
//		response.sendRedirect("/ServletProj/direct/rs1");
		String num=request.getParameter("num");
		String result=request.getAttribute("result").toString();
		PrintWriter out=response.getWriter();
		out.println("<h1>"+num+"累加和为:"+result+"</h1>");
		
	}

}

response.sendRedirect("/ServletProj/direct/~~~~");这个地方最迷糊看别人的好像没有用这个。也不知道什么时候该用

写回答

3回答