java日期处理函数

java中获取本年第一天的日期

public static Timestamp getYearFirstDay() { Calendar calendar = Calendar.getInstance(TimeZone.getTimeZone("GMT+8:00"));// 设置时区~如果使用UTC时区，可以不用设置 int year = calendar.get(Calendar.YEAR); calendar.clear(); calendar.set(Calendar.YEAR, year); return new Timestamp(calendar.getTimeInMillis());}

输出结果：

2016-01-01 00:00:00.0

 

java中获取本周第一天的日期

public static Timestamp getMondayTime() { Calendar calendar = Calendar.getInstance(TimeZone.getTimeZone("GMT+8:00"));// 设置时区~如果使用UTC时区，可以不用设置 calendar.setTimeInMillis(System.currentTimeMillis()); calendar.set(Calendar.HOUR_OF_DAY, 0); calendar.set(Calendar.MINUTE, 0); calendar.set(Calendar.SECOND, 0); calendar.set(Calendar.MILLISECOND, 0); int dayWeek = calendar.get(Calendar.DAY_OF_WEEK); if (1 == dayWeek) { calendar.add(Calendar.DAY_OF_MONTH, -1); } calendar.setFirstDayOfWeek(Calendar.MONDAY); //设置周一为一周的第一天，否则默认是周日 int day = calendar.get(Calendar.DAY_OF_WEEK); //一周有多少天 calendar.add(Calendar.DATE, calendar.getFirstDayOfWeek() - day); return new Timestamp(calendar.getTimeInMillis()); }

 获取上个月的第一天：

// 获取上个月的第一天 public static Timestamp getFirstDayForLastMonth() { Calendar calendar = Calendar.getInstance(TimeZone.getTimeZone("GMT+8:00")); calendar.add(Calendar.MONTH, -1); calendar.set(Calendar.DAY_OF_MONTH, 1); return new Timestamp(calendar.getTimeInMillis()); }

 

 

获取上个月的最后一天：

// 获取上个月的最后一天 public static Timestamp getLastDayForLastMonth() { Calendar calendar = Calendar.getInstance(TimeZone.getTimeZone("GMT+8:00")); calendar.set(Calendar.DAY_OF_MONTH, 0); return new Timestamp(calendar.getTimeInMillis()); }

 

转载于:https://www.cnblogs.com/sonofelice/p/6178126.html