Calendar.getInstance()获取指定时间点(定时)-白红宇

使用Calendar.getInstance()不仅能获取当前的时间，还能指定需要获取的时间点，在项目应用中达到

定时的作用，下面是常用的一些指定时间点使用：

public class Test1 {    public static void main(String[]args){        System.out.println("时间为：\n"+getDate1()+"\n"+getDate2()+"\n"+getDate3()+"\n"+getDate4()+"\n"+getDate5());    }	/*	Calendar.HOUR_OF_DAY 	24小时制	Calendar.HOUR 	12小时制*/		//获取当天0点时间	public static String getDate1(){		 Calendar cal = Calendar.getInstance();		 cal.set(Calendar.HOUR_OF_DAY, 0);//控制时		 cal.set(Calendar.MINUTE, 0);//控制分		 cal.set(Calendar.SECOND, 0);//控制秒		 SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");		 return sdf.format(cal.getTime());	}		//获取当天12点时间	public static String getDate2(){		 Calendar cal = Calendar.getInstance();		 cal.set(Calendar.HOUR_OF_DAY, 12);		 cal.set(Calendar.MINUTE, 0);		 cal.set(Calendar.SECOND, 0);		 SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");		 return sdf.format(cal.getTime());	}			//获取本周一0点时间	public static String getDate3(){		 Calendar cal = Calendar.getInstance();		 cal.set(cal.get(Calendar.YEAR),cal.get(Calendar.MONDAY), cal.get(Calendar.DAY_OF_MONTH), 0, 0,0);		 cal.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);		 SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");		 return sdf.format(cal.getTime());	}			//获取本月第一天0点时间	public static String getDate4(){		 Calendar cal = Calendar.getInstance();		 cal.set(cal.get(Calendar.YEAR),cal.get(Calendar.MONDAY), cal.get(Calendar.DAY_OF_MONTH), 0, 0,0);		 cal.set(Calendar.DAY_OF_MONTH,cal.getActualMinimum(Calendar.DAY_OF_MONTH));		 SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");		 return sdf.format(cal.getTime());	}	         //获得本月最后一天24点时间	public static String getDate5(){		 Calendar cal = Calendar.getInstance();		 cal.set(cal.get(Calendar.YEAR),cal.get(Calendar.MONDAY), cal.get(Calendar.DAY_OF_MONTH), 0, 0,0);		 cal.set(Calendar.DAY_OF_MONTH,cal.getActualMaximum(Calendar.DAY_OF_MONTH));		 cal.set(Calendar.HOUR_OF_DAY, 24);		 SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");		 return sdf.format(cal.getTime());	}		}

控制台输出如下：

参考链接：