日期工具类

工具类

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.List;
import java.util.Locale;


/**
 * Created by qd on 2015/10/26.
 */
public class DateUtil {
    
    
    public static String getYesterday() {
        DateFormat format = new SimpleDateFormat("yyyy-MM-dd");
        Calendar calendar = Calendar.getInstance();
        calendar.add(Calendar.DAY_OF_MONTH, -1);

        return format.format(calendar.getTime());
    }

	public static List<String> getDateList() {

		List<String> dateList = new ArrayList<String>();
		Calendar cal = Calendar.getInstance();
		cal.setTime(new Date());
		cal.set(Calendar.DAY_OF_MONTH, 1);
		dateList.add(new SimpleDateFormat("yyyy-MM-dd").format(cal.getTime()));
		cal.set(Calendar.DAY_OF_MONTH, 2);
		dateList.add(new SimpleDateFormat("yyyy-MM-dd").format(cal.getTime()));
		cal.roll(Calendar.DAY_OF_MONTH, -2);
		dateList.add(new SimpleDateFormat("yyyy-MM-dd").format(cal.getTime()));
		cal.roll(Calendar.DAY_OF_MONTH, -1);
		dateList.add(new SimpleDateFormat("yyyy-MM-dd").format(cal.getTime()));

		return dateList;
	}

	public static Long getStartTime() {
		Calendar todayStart = Calendar.getInstance();
		todayStart.set(Calendar.HOUR_OF_DAY, 0);
		todayStart.set(Calendar.MINUTE, 0);
		todayStart.set(Calendar.SECOND, 0);
		todayStart.set(Calendar.MILLISECOND, 0);
		return todayStart.getTime().getTime();
	}

	public static Long getEndTime() {
		Calendar todayEnd = Calendar.getInstance();
		todayEnd.set(Calendar.HOUR_OF_DAY, 23);
		todayEnd.set(Calendar.MINUTE, 59);
		todayEnd.set(Calendar.SECOND, 59);
		todayEnd.set(Calendar.MILLISECOND, 999);
		return todayEnd.getTime().getTime();
	}

	// 获取每月的天�?
	public static int getDaysByMonth() {
		Calendar cal = Calendar.getInstance(Locale.CHINA);
		return cal.getActualMaximum(Calendar.DATE);
	}

	// 获取当前的月�?
	public static int getMonth() {
		Calendar cal = Calendar.getInstance(Locale.CHINA);
		int month = cal.get(Calendar.MONTH) + 1;
		return month;
	}
	// 获取当月天数
	public static int getDay() {
		Calendar cal = Calendar.getInstance(Locale.CHINA);
		int day = cal.get(Calendar.DAY_OF_MONTH);    //获取当前天数
		return day;
	}

	// 获取月份第一�?
	public static Date getDate(int monthNum,int dayNum) {
		SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
		// 获取当前月第�?天：
		Calendar cc = Calendar.getInstance();
		cc.add(Calendar.MONTH, monthNum);
		cc.set(Calendar.DAY_OF_MONTH, dayNum);// 设置�?1�?,当前日期既为本月第一�?
		String first = format.format(cc.getTime());
		String str = first+" 00:00:00";
		Date d = null;
		try {
			d = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss").parse(str);
		} catch (ParseException e) {
			e.printStackTrace();
		}
		return d;
	}


	public static String timeStampToStr(Long  timeStamp){

		Date date = new Date();
		date.setTime(timeStamp);
		SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");
		String str=sdf.format(date);
		return  str;
	}


	public static Long getFirstDayOfMonth(int year, int month) {
		Calendar cal = Calendar.getInstance();
		cal.set(Calendar.YEAR, year);
		cal.set(Calendar.MONTH, month-1);
		cal.set(Calendar.DAY_OF_MONTH,cal.getMinimum(Calendar.DATE));
		cal.set(Calendar.HOUR_OF_DAY ,0);
		cal.set(Calendar.SECOND, 0);
		cal.set(Calendar.MINUTE, 0);
		cal.set(Calendar.MILLISECOND, 001);
		return  cal.getTime().getTime();
	}

	//�?要注意的是：月份是从0�?始的，比如说如果输入5的话，实际上显示的是4月份的最后一天，千万不要搞错了哦
	public static Long getLastDayOfMonth(int year, int month) {
		Calendar cal = Calendar.getInstance();
		cal.set(Calendar.YEAR, year);
		cal.set(Calendar.MONTH, month-1);
		cal.set(Calendar.DATE, cal.getActualMaximum(Calendar.DAY_OF_MONTH));
		cal.set(Calendar.HOUR_OF_DAY ,23);
		cal.set(Calendar.SECOND, 59);
		cal.set(Calendar.MINUTE, 59);
		cal.set(Calendar.MILLISECOND, 999);
		// new   SimpleDateFormat( "yyyy-MM-dd ").format(cal.getTime())
		return   cal.getTime().getTime();
	}

	public static String Date2Str(Date date, String format) {
		if (date == null) return null;
		SimpleDateFormat sdf = new SimpleDateFormat(format);
		String str = sdf.format(date);
		return str;
	}
	
	public static Date parseDate(String sDate, String format) {
        java.text.DateFormat formatter = new java.text.SimpleDateFormat(format);
        java.util.Date retDate = null;
        try {
            retDate = formatter.parse(sDate);
        } catch (Exception ex) {
        }
        return retDate;
    }

	
	public static void main(String args[]) throws ParseException {
//		System.out.println(getFirstDayOfMonth(2017,10));
//		System.out.println(getFirstDayOfMonth(2017,11)-1000);
//    	System.out.println(getMonthLastDay("2017-2"));
		System.out.println(1);
		System.out.println(getDaysByMonth());
		System.out.println(1);
	}
}