获取当前时间的前几个月的星期起始结束时间

每天学习一点点 编程PDF电子书、视频教程免费下载：
http://www.shitanlife.com/code

实现的效果打印出来如下：

第4月第1周----------2018-4-2===2018-4-8
第4月第2周----------2018-4-9===2018-4-15
第4月第3周----------2018-4-16===2018-4-22
第4月第4周----------2018-4-23===2018-4-29
第4月第5周----------2018-4-30===2018-5-6
第5月第1周----------2018-5-7===2018-5-13
第5月第2周----------2018-5-14===2018-5-20

 工具类代码：

@Service
public class ToolsService {
    /**
     * get Calendar of given year
     * @param year
     * @return
     */
    private 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 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 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);    
    } 
}

逻辑代码：

// 获取当前时间在今年的周数
        Date todayDate = new Date();
        Calendar calendar = Calendar.getInstance();
        calendar.setFirstDayOfWeek(Calendar.MONDAY);
        calendar.setTime(todayDate);
        int currentWeekIndex = calendar.get(Calendar.WEEK_OF_YEAR);
        int currentMonthIndex = calendar.get(Calendar.MONTH)+1;
        int currentYear = calendar.get(Calendar.YEAR);
        
        int monthWeekCount = 1;
        int tempMonth = 0;
        
        for(int i=currentWeekIndex-10; i<currentWeekIndex; i++)
        {
            if(i<1)
            {
                continue;
            }
            
            String weekStartTime = toolsService.getStartDayOfWeekNo(currentYear, i);

            int startMonth = Integer.parseInt(weekStartTime.split("-")[1]);
            if(startMonth < currentMonthIndex - 1)
            {
                continue;
            }
            
            if(tempMonth != startMonth)
            {
                tempMonth = startMonth;
                monthWeekCount = 1;
            }
            
            String weekEndTime = toolsService.getEndDayOfWeekNo(currentYear, i);
            System.out.println("第" + startMonth + "月第" + monthWeekCount +"周----------" +weekStartTime + "===" + weekEndTime);

            monthWeekCount ++;
        }

每天学习一点点 编程PDF电子书、视频教程免费下载：
http://www.shitanlife.com/code