java 获取当前天之后或之前7天日期----/获取指定时间的前一天或者后一天时间/(工具类)

/*** 获得指定日期的前一天* @param specifiedDay* @return* @throws Exception*/public static String getSpecifiedDayBefore(String specifiedDay){Calendar c = Calendar.getInstance();Date date=null;try {date = new SimpleDateFormat("yy-MM-dd").parse(specifiedDay);} catch (ParseException e) {e.printStackTrace();}c.setTime(date);int day=c.get(Calendar.DATE);c.set(Calendar.DATE,day-1);String dayBefore=new SimpleDateFormat("yyyy-MM-dd").format(c.getTime());return dayBefore;}/*** 获得指定日期的后一天* @param specifiedDay* @return*/public static String getSpecifiedDayAfter(String specifiedDay){Calendar c = Calendar.getInstance();Date date=null;try {date = new SimpleDateFormat("yy-MM-dd").parse(specifiedDay);} catch (ParseException e) {e.printStackTrace();}c.setTime(date);int day=c.get(Calendar.DATE);c.set(Calendar.DATE,day+1);String dayAfter=new SimpleDateFormat("yyyy-MM-dd").format(c.getTime());return dayAfter;}/** * 获取过去或者未来 任意天内的日期数组 * @param intervalsintervals天内 * @return 日期数组 */ public static ArrayList<String> test(int intervals ) { ArrayList<String> pastDaysList = new ArrayList<>(); ArrayList<String> fetureDaysList = new ArrayList<>(); for (int i = 0; i <intervals; i++) { pastDaysList.add(getPastDate(i)); fetureDaysList.add(getFetureDate(i)); } return pastDaysList; } /** * 获取过去第几天的日期 * * @param past * @return */ public static String getPastDate(int past) { Calendar calendar = Calendar.getInstance(); calendar.set(Calendar.DAY_OF_YEAR, calendar.get(Calendar.DAY_OF_YEAR) - past); Date today = calendar.getTime(); SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd"); String result = format.format(today); return result; } /** * 获取未来 第 past 天的日期 * @param past * @return */ public static String getFetureDate(int past) { Calendar calendar = Calendar.getInstance(); calendar.set(Calendar.DAY_OF_YEAR, calendar.get(Calendar.DAY_OF_YEAR) + past); Date today = calendar.getTime(); SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd"); String result = format.format(today); return result; }