获取某一年指定自然周的开始时间和结束时间

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获取某一年指定自然周的开始时间和结束时间

package com.playmath.playmathcrm.util;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;

/**
 * Created by gailun on 2018/8/11.
 */
public class WeekUtils {
    public static void main(String[] args) throws ParseException {

        WeekUtils cd = new WeekUtils();
        System.out.println("开始时间: " + cd.getStartDayOfWeekNo(2018,32) );
        System.out.println("结束时间:" + cd.getEndDayOfWeekNo(2018,32) );
        String startDayOfWeekNo = cd.getStartDayOfWeekNo(2018, 32);
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        System.out.println(sdf.parse(startDayOfWeekNo));
        System.out.println(sdf.format(sdf.parse(startDayOfWeekNo)));

    }

    /**
     * get first date of given month and year
     * @param year
     * @param month
     * @return
     */
    public static String getFirstDayOfMonth(int year,int month){
        String monthStr = month < 10 ? "0" + month : String.valueOf(month);
        return year + "-"+monthStr+"-" +"01";
    }

    /**
     * get the last date of given month and year
     * @param year
     * @param month
     * @return
     */
    public static String getLastDayOfMonth(int year,int month){
        Calendar calendar = Calendar.getInstance();
        calendar.set(Calendar.YEAR , year);
        calendar.set(Calendar.MONTH , month - 1);
        calendar.set(Calendar.DATE , 1);
        calendar.add(Calendar.MONTH, 1);
        calendar.add(Calendar.DAY_OF_YEAR , -1);
        return calendar.get(Calendar.YEAR) + "-" + (calendar.get(Calendar.MONTH) + 1) + "-" +
                calendar.get(Calendar.DAY_OF_MONTH);
    }

    /**
     * get Calendar of given year
     * @param year
     * @return
     */
    private static Calendar getCalendarFormYear(int year){
        Calendar cal = Calendar.getInstance();
        cal.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
        cal.set(Calendar.YEAR, year);
        return cal;
    }

    /**
     * get start date of given week no of a year
     * @param year
     * @param weekNo
     * @return
     */
    public static String getStartDayOfWeekNo(int year,int weekNo){
        Calendar cal = getCalendarFormYear(year);
        cal.set(Calendar.WEEK_OF_YEAR, weekNo);
        return cal.get(Calendar.YEAR) + "-" + (cal.get(Calendar.MONTH) + 1) + "-" +
                cal.get(Calendar.DAY_OF_MONTH);

    }

    /**
     * get the end day of given week no of a year.
     * @param year
     * @param weekNo
     * @return
     */
    public static String getEndDayOfWeekNo(int year,int weekNo){
        Calendar cal = getCalendarFormYear(year);
        cal.set(Calendar.WEEK_OF_YEAR, weekNo);
        cal.add(Calendar.DAY_OF_WEEK, 6);
        return cal.get(Calendar.YEAR) + "-" + (cal.get(Calendar.MONTH) + 1) + "-" +
                cal.get(Calendar.DAY_OF_MONTH);
    }


}

执行结果: