Java 日期时间处理工具类

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.Locale;
import java.util.TimeZone;

public class DateTimeUtil {
	public static int getMonth(Date date) {
		Calendar calendar = new GregorianCalendar();
		calendar.setTime(date);
		return calendar.get(Calendar.MONTH)+1;
	}
	
	public static String getMonth2(Date date) {
		int month = getMonth(date);
		if(month<10) {
			return "0"+month;
		}else {
			return ""+month;
		}
	}
	
	public static int getDay(Date date) {
		Calendar calendar = new GregorianCalendar();
		calendar.setTime(date);
		return calendar.get(Calendar.DATE);
	}
	
	public static String getDay2(Date date) {
		int day = getDay(date);
		if(day<10) {
			return "0"+day;
		}else {
			return ""+day;
		}
	}
	
	public static int getHour(Date date) {
		Calendar calendar = new GregorianCalendar();
		calendar.setTime(date);
		return calendar.get(Calendar.HOUR_OF_DAY);
	}
	
	public static int getYear(Date date) {
		Calendar calendar = new GregorianCalendar();
		calendar.setTime(date);
		return calendar.get(Calendar.YEAR);
	}
	
	public static int getEndDay(int year,int month) {
		if(month == 1||month == 3||month == 5||month == 7||month == 8||month == 10||month == 12) {
			return 31;
		}else if(month == 4||month == 6||month == 9||month == 11){
			return 30;
		}else if(month == 2) {
			if((year%400 == 0) || (year%4 == 0 && year%100 != 0 )){
				return 29;
			}else {
				return 28;
			}
		}
		return 30;
	}
	
	public static Date parseDateFromCST(String time) throws ParseException {
		SimpleDateFormat sdf = new SimpleDateFormat("EEE MMM dd HH:mm:ss zzz yyyy", Locale.US);
		sdf.setTimeZone(TimeZone.getTimeZone("GMT+8"));
		return sdf.parse(time);
	}
	
	/**
     * 根据日期获取 星期 （2019-05-06 ——> 星期一）
     * @param datetime
     * @return
     */
    public static int dateToWeek(String datetime) {
        SimpleDateFormat f = new SimpleDateFormat("yyyy-MM-dd");
        int[] weekDays = {7, 1, 2, 3, 4, 5, 6};
        Calendar cal = Calendar.getInstance();
        Date date;
        try {
            date = f.parse(datetime);
            cal.setTime(date);
        } catch (ParseException e) {
            e.printStackTrace();
        }
        //一周的第几天
        int w = cal.get(Calendar.DAY_OF_WEEK) - 1;
        if (w < 0)
            w = 0;
        return weekDays[w];
    }
    
    public static Date datetimeCalculate(Date inputDatetime, int unit, int count) {
    	Calendar calendar = new GregorianCalendar();
    	calendar.setTime(inputDatetime);
    	calendar.add(unit,count);
    	return calendar.getTime();
    }
}