考试计时并自动提交试卷

package com.wgh.servlet; import com.wgh.tools.StringUtil; import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; /** * * @author administrator */ public class StartExam extends HttpServlet { protected int examTime=10; //考试时间 protected void processRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html;charset=GBK"); String action = request.getParameter("action"); if("startExam".equals(action)){ this.startExam(request,response); //开始考试 }else if("showStartTime".equals(action)){//显示考试时间 this.showStartTime(request,response); }else if("showRemainTime".equals(action)){//显示剩余时间 this.showRemainTime(request,response); } } public void startExam(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException{ HttpSession session = request.getSession(); request.setAttribute("time", examTime); //保存考试时间 session.setAttribute("startTime",new java.util.Date().getTime()); //保存当前时间的毫秒数 request.getRequestDispatcher("startExam.jsp").forward(request, response); } // 显示考试计时 public void showStartTime(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html;charset=GBK"); HttpSession session = request.getSession(); String startTime=session.getAttribute("startTime").toString(); StringUtil su=new StringUtil(); long a=Long.parseLong(startTime); //将开始时间转换为毫秒数 long b=new java.util.Date().getTime(); //获取当前时间的毫秒数 int h=(int)Math.abs((b-a)/3600000); //获取小时 String hour=su.formatNO(h,2); //将小时格式化为两位 int m=(int)(b-a)%3600000/60000; //获取分钟 String minute=su.formatNO(m,2); //将分钟格式化为两位 int s=(int)((b-a)%3600000)%60000/1000; //获取秒数 String second=su.formatNO(s,2); //将秒数格式化为两位 String time=hour+":"+minute+":"+second; //组合已用时间 request.setAttribute("showStartTime",time);//将生成的时间保存到showStartTime参数中 request.getRequestDispatcher("showStartTime.jsp").forward(request, response); //重定向页面 } public void showRemainTime(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html;charset=GBK"); HttpSession session = request.getSession(); String startTime=session.getAttribute("startTime").toString(); StringUtil su=new StringUtil(); long a=Long.parseLong(startTime); //获取开始时间的毫秒数 long b=new java.util.Date().getTime(); //获取当前时间的毫秒数 long r=examTime*60000-(b-a-1000); //计算考试剩余时间的毫秒数 int h=(int)Math.abs(r/3600000); //计算小时 String hour=su.formatNO(h,2); //将小时格式化为两位 int m=(int)(r)%3600000/60000; //计算分钟 String minute=su.formatNO(m,2); //将分钟格式化为两位 int s=(int)((r)%3600000)%60000/1000; //计算秒数 String second=su.formatNO(s,2); //将秒数格式化为两位小数 String time=hour+":"+minute+":"+second; //组合剩余时间 request.setAttribute("showRemainTime",time); //将生成的时间保存到showRemainTime参数中 request.getRequestDispatcher("showRemainTime.jsp").forward(request, response); //重定向页面 } public void init() throws ServletException { examTime=Integer.parseInt(getInitParameter("examTime")); //获取配置文件中设置的考试时间 } @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { processRequest(request, response); } @Override protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { processRequest(request, response); } @Override public String getServletInfo() { return "Short description"; }// </editor-fold> }