朋友的一个小需求 获取指定年份中每一周 的日期范围 直接上代码
package com.dbappsecurity.nssa.notice; import java.time.DayOfWeek; import java.time.LocalDate; import java.time.format.DateTimeFormatter; import java.time.temporal.WeekFields; import java.util.ArrayList; import java.util.HashMap; import java.util.List; /** * @author lkq * @date 2020/06/30 * @description: **/ public class Test { /** * @param args */ public static void main(String[] args) { List list = new ArrayList<>();//入库数据 //初始化，第一周至少四天,周天数占比 WeekFields wfs = WeekFields.of(DayOfWeek.MONDAY, 4); //一年最后一天日期的LocalDate，如果该天获得的周数为1或52，那么该年就只有52周，否则就是53周 //获取指定时间所在年的周数 for (int y = 0; y < 10; y++) {//y控制年限 int num = LocalDate.of(2020 + y, 12, 31).get(wfs.weekOfWeekBasedYear()); num = num == 1 ? 52 : num; for (int i = 1; i <= num; i++) {//num控制周数 String days = getDay(2020 + y, i, DayOfWeek.MONDAY) + "," + getDay(2020 + y, i, DayOfWeek.TUESDAY) + "," + getDay(2020 + y, i, DayOfWeek.WEDNESDAY) + "," + getDay(2020 + y, i, DayOfWeek.THURSDAY) + "," + getDay(2020 + y, i, DayOfWeek.FRIDAY) + "," + getDay(2020 + y, i, DayOfWeek.SATURDAY) + "," + getDay(2020 + y, i, DayOfWeek.SUNDAY); String[] split = trim(days, ",").split(","); days = split[0] + "~" + split[split.length - 1]; System.out.println(2020 + y + "年,第" + i + "周，日期:" + days); //如果 需要入库,用list即可 HashMap<Object, Object> data = new HashMap<>(); data.put("year", 2020 + y); data.put("week", i); data.put("days", days); list.add(data); } } } private static String getDay(Integer year, Integer num, DayOfWeek dayOfWeek) { //周数小于10在前面补个0 String numStr = num < 10 ? "0" + String.valueOf(num) : String.valueOf(num); //2019-W01-01获取第一周的周一日期，2019-W02-07获取第二周的周日日期 String weekDate = String.format("%s-W%s-%s", year, numStr, dayOfWeek.getValue()); String date = LocalDate.parse(weekDate, DateTimeFormatter.ISO_WEEK_DATE).toString(); String[] split = date.split("-"); if (!split[0].equals(year.toString())) { //返回日期范围属于指定年 return ""; } date = split[1] + "-" + split[2]; return date; } /** * 去除首尾指定字符 * * @param str 字符串 * @param element 指定字符 * @return */ public static String trim(String str, String element) { if (str == null || str.equals("")) return str; boolean beginIndexFlag = true; boolean endIndexFlag = true; do { int beginIndex = str.indexOf(element) == 0 ? 1 : 0; int endIndex = str.lastIndexOf(element) + 1 == str.length() ? str.lastIndexOf(element) : str.length(); str = str.substring(beginIndex, endIndex); beginIndexFlag = (str.indexOf(element) == 0); endIndexFlag = (str.lastIndexOf(element) + 1 == str.length()); } while (beginIndexFlag || endIndexFlag); return str; } }