老师请检查,不知道为什么404,路径检查了没有问题

index.html

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>add-test</title>
</head>
<body>
	<form action="/requestServlet/rq">
		<input type="number" name="num" placeholder="请输入100以内的数字"><input type="submit" name="button" value="求累加和">
	</form>
	
</body>
</html>

REQServlet.java

package com.superj.com;

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 RQEServlet
 */
@WebServlet("/rq")
public class RQEServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public RQEServlet() {
        super();
        // TODO Auto-generated constructor stub
    }

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



}

resultServlet.java

package com.superj.com;

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 resultServlet
 */
@WebServlet("/result")
public class resultServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public resultServlet() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		request.setCharacterEncoding("utf-8");
		response.setCharacterEncoding("utf8");
		response.setContentType("text/html;charset=utf-8");
		int sum2=(int) request.getAttribute("sum");
		response.getWriter().println("累加和为："+sum2);
	}



}

阿姜爱学习 2020-03-24

源自：Servlet与JSP进阶 2-6 自由编程