public class calender {
public static class DateUtil {
private static SimpleDateFormat sdf = new SimpleDateFormat("yyyyMM");
private static Calendar calendar = Calendar.getInstance();
/*
输入日期字符串比如201703,返回当月第一天的Date
*/
public static Date getMinDateMonth(String month) {
try {
Date nowDate = sdf.parse(month);
calendar = Calendar.getInstance();
calendar.setTime(nowDate);
calendar.set(Calendar.DAY_OF_MONTH, calendar.getActualMinimum(Calendar.DAY_OF_MONTH));
return calendar.getTime();
} catch (ParseException e) {
e.printStackTrace();
}
return null;
}
/*
输入日期字符串,返回当月最后一天的Date
*/
public static Date getMaxDateMonth(String month) {
try {
Date nowDate = sdf.parse(month);
calendar = Calendar.getInstance();
calendar.setTime(nowDate);
calendar.set(Calendar.DAY_OF_MONTH, calendar.getActualMaximum(Calendar.DAY_OF_MONTH));
return calendar.getTime();
} catch (ParseException e) {
e.printStackTrace();
}
return null;
}
public static void main(String[] args) throws ParseException {
String month = "201705";
System.out.println(getMinDateMonth(month));
System.out.println(getMaxDateMonth(month));
}
}
}
代码执行结果:
Mon May 01 00:00:00 CST 2017
Wed May 31 00:00:00 CST 2017