使用Calendar.getInstance()不僅能獲取當前的時間,還能指定需要獲取的時間點,在項目應用中達到
定時的作用,下面是常用的一些指定時間點使用:
public class Test1 {
public static void main(String[]args){
System.out.println("時間爲:\n"+getDate1()+"\n"+getDate2()+"\n"+getDate3()+"\n"+getDate4()+"\n"+getDate5());
}
/* Calendar.HOUR_OF_DAY 24小時制
Calendar.HOUR 12小時制*/
//獲取當天0點時間
public static String getDate1(){
Calendar cal = Calendar.getInstance();
cal.set(Calendar.HOUR_OF_DAY, 0);//控制時
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());
}
//獲取當天12點時間
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());
}
//獲取本週一0點時間
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());
}
//獲取本月第一天0點時間
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());
}
//獲得本月最後一天24點時間
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());
}
}
控制檯輸出如下
轉自: https://blog.csdn.net/alan_liuyue/article/details/71191037