java获取当前周或当前月的（开始日期-结束日期）

 

package com.sangame.uc.front.web.controller.front;
 
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
 
/**
 *  目前最正确的解决方案：获取当前日期的周一和周日，月初和月末
 */
public class DateUtils {
    private static SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
 
    public static void main(String args[]){
        System.out.println(getCurrentMonday());
        System.out.println(getPreviousSunday());
        System.out.println(getMinMonthDate("2017-04-17"));
        System.out.println(getMaxMonthDate("2017-04-17"));
    }
    // 获得本周一与当前日期相差的天数
    public static  int getMondayPlus() {
        Calendar cd = Calendar.getInstance();
        int dayOfWeek = cd.get(Calendar.DAY_OF_WEEK);
        if (dayOfWeek == 1) {
            return -6;
        } else {
            return 2 - dayOfWeek;
        }
    }
 
    // 获得当前周- 周一的日期
    public static  String getCurrentMonday() {
        int mondayPlus = getMondayPlus();
        GregorianCalendar currentDate = new GregorianCalendar();
        currentDate.add(GregorianCalendar.DATE, mondayPlus);
        Date monday = currentDate.getTime();
        DateFormat df = DateFormat.getDateInstance();
        String preMonday = df.format(monday);
        return preMonday;
    }
 
 
    // 获得当前周- 周日  的日期
    public static String getPreviousSunday() {
        int mondayPlus = getMondayPlus();
        GregorianCalendar currentDate = new GregorianCalendar();
        currentDate.add(GregorianCalendar.DATE, mondayPlus +6);
        Date monday = currentDate.getTime();
        DateFormat df = DateFormat.getDateInstance();
        String preMonday = df.format(monday);
        return preMonday;
    }
    // 获得当前月--开始日期
    public static String getMinMonthDate(String date) {
        Calendar calendar = Calendar.getInstance();
        try {
            calendar.setTime(dateFormat.parse(date));
            calendar.set(Calendar.DAY_OF_MONTH, 
            calendar.getActualMinimum(Calendar.DAY_OF_MONTH));
            return dateFormat.format(calendar.getTime());
        } catch (java.text.ParseException e) {
            e.printStackTrace();
        }
        return null;
    }
 
    // 获得当前月--结束日期
    public static String getMaxMonthDate(String date){
        Calendar calendar = Calendar.getInstance();
        try {
            calendar.setTime(dateFormat.parse(date));
            calendar.set(Calendar.DAY_OF_MONTH,         
            calendar.getActualMaximum(Calendar.DAY_OF_MONTH));
            return dateFormat.format(calendar.getTime());
        }  catch (java.text.ParseException e) {
            e.printStackTrace();
        }
        return null;
    }
}