Java实现在线考试系统与设计（学生功能）

@InitBinder
	public void initBinder(WebDataBinder binder) {
		SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
		binder.registerCustomEditor(Date.class, new CustomDateEditor(dateFormat, true));
	}
	
	@RequestMapping("/list")
	public String showExam(HttpServletRequest request,Integer curr, Model model){
		if (curr == null){
			curr = 1;
		}
		HttpSession session = request.getSession();
		Student student = (Student) session.getAttribute("studentInfo");
		Integer classesid = student.getClassesid();
		if (classesid != null){
			PageInfo<Publishexam> publishexamList = publishExamService.selectAll(classesid, curr, 5);
			model.addAttribute("publishexamList", publishexamList);
		}
		model.addAttribute("studentInfo", student);
		return "/exam/list";
	}
	
	//进入考试页面，初始化数据
	@SuppressWarnings("unchecked")
	@RequestMapping("/exam")
	public String exam(HttpServletRequest request,int id,Model model){
		
		//0表示0.5小时，1表示1小时，2表示1.5小时，3表示2小时，4表示2.5小时，5表示3小时
		//考试时间所对应的毫秒数
		long[] dateLong = {30*60*1000, 60*60*1000, 90*60*1000, 120*60*1000, 150*60*1000, 180*60*1000};
		
		PublishexamWithBLOBs publishexam = publishExamService.selectByKey(id);
		HttpSession session = request.getSession();
		Student student = (Student) session.getAttribute("studentInfo");
		
		//在考试记录表中添加一条考试信息
		Examhis examhis = examhisService.studentIsNotExam(student.getId(), publishexam.getSubjectId(), publishexam.getExamtime());
		List<Text> textList = null;
		ArrayList<TextModel> list = JsonUtils.toBean(publishexam.getExam(), ArrayList.class, TextModel.class);
		Date date = new Date();
		Date date2 = new Date();
		date2.setTime(publishexam.getExamtime().getTime() + dateLong[publishexam.getExamlength()]);
		//当前时间如果在考试时间之前,考试还未开始
		if (date.compareTo(publishexam.getExamtime()) <= 0){
			model.addAttribute("message", "对不起当前考试还未开始!");
			return "/message";
		}
		
		/*1.当前时间>考试时间+考试时长，考试已经结束
		 2.examhis=null，则证明作者第一次点击开始考试
			如果examhis不为空
				状态为1:表示正在考试
				状态为2:表示已经考试结束，
				状态为3:表示老师已经阅完试卷
		*/
		if (date.compareTo(date2) >= 0 || (examhis != null && examhis.getStatus() != 1)){
			model.addAttribute("message", "对不起当前考试已经结束!");
			return "/message";
		}
		if (examhis == null){
			examhis = new Examhis();
			examhis.setStudentid(student.getId());
			examhis.setStudentname(student.getName());
			examhis.setSubjectid(publishexam.getSubjectId());
			examhis.setSubjectname(publishexam.getSubjectName());
			examhis.setClassesid(student.getClassesid());
			examhis.setClassesname(student.getClassesname());
			examhis.setPublishexamid(id);
			examhis.setExamtime(publishexam.getExamtime());
			examhis.setStatus(1);		
			textList = new ArrayList<Text>();		
			for (TextModel textModel : list) {
				List<Text> text = textService.beginExam(textModel,publishexam.getSubjectId());
				for (Text text2 : text) {
					text2.setTexId(textModel.getTextModelId());
				}
				textList.addAll(text);
			}
			String json = JsonUtils.toJson(textList);
			examhis.setExamtest(json);
			examhisService.insert(examhis);
		}else{
			textList = JsonUtils.toBean(examhis.getExamtest(), ArrayList.class, Text.class);
		}
		
		int sum = 0;
		for (TextModel textModel : list) {
			sum += textModel.getGrade()*textModel.getTextCount();
		}
		List<Textmodel> textModelList = textModelService.selectTextModel(list);
		model.addAttribute("textModelList", textModelList);
		model.addAttribute("studentInfo", student);
		model.addAttribute("textList", textList);
		model.addAttribute("publishexam", publishexam);
		model.addAttribute("sum", sum);
		model.addAttribute("examTimeLength", dateLong[publishexam.getExamlength()]/1000);
		model.addAttribute("examTime", (date2.getTime() - date.getTime())/1000);
		return "/exam/exam";
	}
	
	//提交考试方法
	@RequestMapping(value="/examEnd", method=RequestMethod.POST)
	@ResponseBody
	public AjaxResult examEnd(HttpServletRequest request, ExamList examList, int id){
		PublishexamWithBLOBs publishexam = publishExamService.selectByKey(id);
		HttpSession session = request.getSession();
		Student student = (Student) session.getAttribute("studentInfo");
		//将考试信息转成json，改变考试状态，更新到考试历史记录表中
		Examhis examhis = examhisService.studentIsNotExam(student.getId(), publishexam.getSubjectId(), publishexam.getExamtime());
		List<Exam> list = examList.getExamList();
		list.remove(0);
		for (Exam exam : list) {
			exam.setText(textService.selectOne(exam.getTextId()));
			if (exam.getAnswer() == null){
				exam.setAnswer(" ");
			}
		}
		String json = JsonUtils.toJson(list);
		examhis.setExamtest(json);
		examhis.setStatus(2);
		examhisService.update(examhis);
		return AjaxResult.successInstance("您已成功提交考试");
	}

 <script type="text/javascript">
 //JS实现倒计时，考试结束提交试卷
 function startTime(){ 
 	//定义考试剩余时间，时间为毫秒数
  //examTime = "${examTime}";//对考试剩余时间赋值
 	//var exam = parseInt("${examTime}");
 	var examTime = parseInt(examTimes.innerHTML); 
	 var examTimeLength;//考试时长
	 examTimeLength = "${examTimeLength}"; 
	 if ((examTime)<0){
	 	alert("考试时间到!\n即将提交试卷!");
	 	document.forms[0].submit();
	 }else{
	 	//var lm = Math.floor((examTimeLength - examTime) / 60000);
	 	var lh = Math.floor(((examTimeLength - examTime) / 3600) % 60)
	 	var lm = Math.floor(((examTimeLength - examTime) / 60) % 60);
	 	var ls = (examTimeLength - examTime) % 60;
	 	var yh = Math.floor((examTime / 3600) % 60);
	 	var ym = Math.floor((examTime / 60) % 60);
	 	var ys = examTime % 60;
	  document.getElementById("tTime").innerHTML = "考试已经开始了" + lh + "时" + lm + "分" + ls + "秒" + ",剩余" + yh + "时" + ym + "分" + ys + "秒";
	 }
	 examTime--;
	 examTimes.innerHTML=examTime;
	 setTimeout(startTime,1000);
 }
 var timer=null;
 //当页面加载后，启动周期性定时器，每过1秒执行startTime
 window.onload=function(){
 	startTime();
 }
 </script>