这篇文章主要为大家详细介绍了Java制作投票系统,文中示例代码介绍的非常详细,零基础也能参考此文章,感兴趣的小伙伴们可以参考一下。

代码展示:

package com.tarena.wgh.servlet;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.*;

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

public class PollServlet extends HttpServlet {


/**

* The doPost method of the servlet. <br> * * This method is called when a form has its tag value method equals to post. * * @param request the request send by the client to the server * @param response the response send by the server to the client * @throws ServletException if an error occurred * @throws IOException if an error occurred */public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("GBK"); //设置请求的编码方式 String item=request.getParameter("item"); //获取投票项 ServletContext servletContext=request.getSession().getServletContext(); //获取ServletContext对象该对象在application范围内有效 Map map=null; if(servletContext.getAttribute("pollResult")!=null){ map=(Map)servletContext.getAttribute("pollResult"); //获取投票结果 map.put(item,Integer.parseInt(map.get(item).toString())+1); //将当前的投票项加1 }else{ //初始化一个保存投票信息的Map集合,并将选定投票项的投票数设置为1,其他为0 String[] arr={"基础教程类","实例集锦类","经验技巧类","速查手册类","案例剖析类"}; map=new HashMap(); for(int i=0;i<arr.length;i++){ if(item.equals(arr[i])){ //判断是否为选定的投票项 map.put(arr[i], 1); }else{ map.put(arr[i], 0); } } } servletContext.setAttribute("pollResult", map); //保存投票结果到ServletContext对象中 response.setCharacterEncoding("GBK"); //设置响应的编码方式,如果不设置弹出的对话框中的文字将乱码 PrintWriter out=response.getWriter(); out.println("<script>alert('投票成功!');window.location.href='showResult.jsp';</script>");}}

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