日期使用的总结

/** * 计算年龄 * @Title: getAge  * @Description: TODO * @param dateOfBirth yyyyMMdd * @return * @throws */private int getAge(long dateOfBirth) {Date dbDate = null;SimpleDateFormat dateFormat = new SimpleDateFormat("yyyyMMdd");try {dbDate = (Date) dateFormat.parse(String.valueOf(dateOfBirth));} catch (ParseException e) {e.printStackTrace();}int age = 0;Calendar born = Calendar.getInstance();Calendar now = Calendar.getInstance();if (dbDate != null) {now.setTime(new Date());born.setTime(dbDate);if (born.after(now)) {throw new IllegalArgumentException("Can't be born in the future");}age = now.get(Calendar.YEAR) - born.get(Calendar.YEAR);if (now.get(Calendar.DAY_OF_YEAR) < born.get(Calendar.DAY_OF_YEAR)) {age -= 1;}}return age;}

/** * 删除比较老的LOG文件（删除指定天数之前的LOG文件） * @Title: deleteFile  * @param saveDateNum log文件保存的天数 * @throws */private void deleteFile(int saveDateNum){Log.d(TAG, "deleteFile saveDateNum = " + saveDateNum);if(saveDateNum == 0){saveDateNum = 3;}List<String> dateList = new ArrayList<String>();String rootPath = GlobalData.getInstance().appMainFolder;String path = rootPath + "/Log_Test/";Date date = new Date();for(int i = 0 ; i < saveDateNum ; i ++){// 获得日期Calendar calendar = Calendar.getInstance();calendar.setTime(date);calendar.add(Calendar.DAY_OF_MONTH, -1);date = calendar.getTime();// 删除文件SimpleDateFormat formatter = new SimpleDateFormat("yyyyMMdd");String fileName = formatter.format(date) + "_log.txt";dateList.add(fileName);}Log.d(TAG, "deleteFile saveList = " + dateList);File dirFile = new File(path);File [] deleteFiles = dirFile.listFiles();for(int j = 0 ; j < deleteFiles.length ; j ++){File f = deleteFiles[j];if(!dateList.contains(f.getName())){Log.d(TAG, "deleteFile delete file name  = " + f.getName());if(f.exists()){f.delete();}}}}