Java-通过年和月获取当前月有几个周一并获取周一的日期
业务需求想获取一个月中的有几个周一，并获取对应的日期，在网上找了一圈， 没找到，就动手写了一个，记录下。
直接上代码：
import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.Calendar;import java.util.LinkedList;import java.util.List;import com.alibaba.fastjson.JSONObject;public class DateUtilWeek {public static void main(String[] args) throws ParseException {getWeekS(, 1);}public static JSONObject getWeekS(Integer year, Integer month) throws ParseException {List<String> weeks = new LinkedList<>();int tongji = 0;Calendar c = Calendar.getInstance();c.set(year, month - 1, 1);int mountDay = c.getActualMaximum(Calendar.DAY_OF_MONTH);SimpleDateFormat sim = new SimpleDateFormat("yyyy-MM-dd E");SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");for (int i=1;i<=mountDay;i++) {String date1 = year + "-";if (month < 10) {date1 += "0" + month + "-";} else {date1 += month + "-";}if (i < 10) {date1 += "0" + i;} else {date1 += i;}String dateStr = sim.format(sdf.parse(date1));String weekStr = dateStr.substring(11,14);if ("星期一".equals(weekStr)) {weeks.add(date1);tongji++;}}JSONObject data = new JSONObject();data.put("num", tongji);data.put("list", weeks);return data;}}
