基于java的学生随机点名系统

基于java的学生考勤系统，能显示课程信息，随机点名，记录缺勤名单。

package ultilies;

import java.util.Calendar;
import java.util.Date;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;

public class DateComputationUtility {
	
	
	
	
	public static DateComputationUtility getInstance（）{
		if（utility == null）{
			return new DateComputationUtility（）;
		}
		return utility;
	}
	
	
	
	private DateComputationUtility（）{
		
	}
	
	public int getGapWeeksFromDate（Date startDateDate endDate）{
		int gapDays = getGapDaysFromDate（startDateendDate）;
		int gapWeeks = gapDays/WEEKMETRIC;
		int leftDays = gapDays%WEEKMETRIC;
		
		Calendar calendar = Calendar.getInstance（）;
		calendar.setTime（startDate）;
		int currentWeek = calendar.get（Calendar.WEEK_OF_MONTH）;
		calendar.add（Calendar.DAY_OF_WEEK leftDays）;
		int nextWeek = calendar.get（Calendar.WEEK_OF_MONTH）;
		
		return gapWeeks + nextWeek - currentWeek + 1;
		
	}
	
	private int getGapDaysFromDate（Date startDateDate endDate）{
		long startMills = startDate.getTime（）;
		long currMills = endDate.getTime（）;
		
		return （int）（（currMills - startMills） /MILLMETRIC/HOURMETRIC/HOURMETRIC/DAYMETRIC）;
	}
	
	public int getCurrentLesson（）{
		Calendar calendar = Calendar.getInstance（）;
		calendar.add（Calendar.MINUTE 5）;
		
		int hour = calendar.get（Calendar.HOUR_OF_DAY）;
		if（hour - EVERNINGHOUR > 0）{
			return hour-EVERNINGHOUR + lessonNumberMap.get（EVERNINGHOUR）;
		}
		if（hour - AFTERNOONHOUR > 0）{
			return hour - AFTERNOONHOUR + lessonNumberMap.get（AFTERNOONHOUR）;
		}
		if（hour - MORNINGHOUR > 0）{
			return hour - MORNINGHOUR + lessonNumberMap.get（MORNINGHOUR）;
		}
		return -1;
	}
	
	public String getCurrentWeekDay（）{
		Calendar calendar = Calendar.getInstance（Locale.CHINA）;
		calendar.setFirstDayOfWeek（Calendar.SUNDAY）;
		
		
		return calendar.getDisplayName（Calendar.DAY_OF_WEEK Calendar.LONG Locale.CHINA）;
	}
	
	public static DateComputationUtility utility;
	
	private static final int MILLMETRIC = 1000;
	private static final int HOURMETRIC = 60;
	private static final int DAYMETRIC = 24;
	private static final int WEEKMETRIC = 7;
	
	public static final int MORNINGHOUR = 8;
	public static final int AFTERNOONHOUR = 14;
	public static final int EVERNINGHOUR = 19;
	
	private static final Map lessonNumberMap = new HashMap（）;
	static {
		lessonNumberMap.put（MORNINGHOUR 1）;
		lessonNumberMap.put（AFTERNOONHOUR 5）;
		lessonNumberMap.put（EVERNINGHOUR 9）;
	}
}

 属性            大小     日期    时间   名称
----------- ---------  ---------- -----  ----

     文件        301  2016-12-19 19:14  StudentDemo\.classpath

     文件        387  2016-12-19 19:14  StudentDemo\.project

     文件        629  2016-12-19 19:14  StudentDemo\.settings\org.eclipse.jdt.core.prefs

     文件       2773  2016-12-22 18:58  StudentDemo\bin\ultilies\DateComputationUtility.class

     文件       1503  2016-12-22 18:58  StudentDemo\bin\ultilies\LabelStringConstructor.class

     文件        969  2016-12-22 18:58  StudentDemo\bin\ultilies\LoadStudentNames.class

     文件       1611  2016-12-22 18:58  StudentDemo\bin\ultilies\LoadStudentNamesService.class

     文件       1074  2016-12-22 18:58  StudentDemo\bin\ultilies\UpdateStringTask.class

     文件       1677  2016-12-22 18:58  StudentDemo\bin\views\AbsentData.class

     文件       1500  2016-12-22 18:58  StudentDemo\bin\views\Studentframe$1.class

     文件       1370  2016-12-22 18:58  StudentDemo\bin\views\Studentframe$2.class

     文件        724  2016-12-22 18:58  StudentDemo\bin\views\Studentframe$3.class

     文件        570  2016-12-22 18:58  StudentDemo\bin\views\Studentframe$4.class

     文件       1359  2016-12-22 18:58  StudentDemo\bin\views\Studentframe$AskStudentName.class

     文件       1571  2016-12-22 18:58  StudentDemo\bin\views\Studentframe$LoadStudentNames.class

     文件       1213  2016-12-22 18:58  StudentDemo\bin\views\Studentframe$ShowAbsentInfo.class

     文件       7122  2016-12-22 18:58  StudentDemo\bin\views\Studentframe.class

     文件       2507  2016-12-19 19:14  StudentDemo\src\ultilies\DateComputationUtility.java

     文件        850  2016-12-19 19:14  StudentDemo\src\ultilies\LabelStringConstructor.java

     文件        761  2016-12-19 19:14  StudentDemo\src\ultilies\LoadStudentNames.java

     文件        952  2016-12-21 18:34  StudentDemo\src\ultilies\LoadStudentNamesService.java

     文件        603  2016-12-19 19:14  StudentDemo\src\ultilies\UpdateStringTask.java

     文件        673  2016-12-21 23:26  StudentDemo\src\views\AbsentData.java

     文件       7269  2016-12-21 23:27  StudentDemo\src\views\Studentframe.java

     文件         21  2016-12-19 19:14  StudentDemo\stuName.txt

     目录          0  2018-04-04 20:22  StudentDemo\bin\ultilies

     目录          0  2018-04-04 20:22  StudentDemo\bin\views

     目录          0  2018-04-04 20:22  StudentDemo\src\ultilies

     目录          0  2018-04-04 20:22  StudentDemo\src\views

     目录          0  2018-04-04 20:22  StudentDemo\.settings

............此处省略6个文件信息