private static final SimpleDateFormat dateymd = new SimpleDateFormat("yyyy-MM-dd");
 private static final SimpleDateFormat dateym = new SimpleDateFormat("yyyy-MM");
 private static final SimpleDateFormat dateymdCN = new SimpleDateFormat("yyyy年MM月dd日");
 private static final SimpleDateFormat dateymdhms = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
 private static final SimpleDateFormat dateymdhmssss = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
 private static final SimpleDateFormat datehms = new SimpleDateFormat("HH:mm:ss");
 private static final SimpleDateFormat dateymdhm = new SimpleDateFormat("yyyy-MM-dd HH:mm");
 private static final SimpleDateFormat dateymdhmsCN = new SimpleDateFormat("yyyy年MM月dd日 HH时mm分ss秒");
 private static final SimpleDateFormat dateymdhmsNum = new SimpleDateFormat("yyyyMMddHHmmss");
 private static final SimpleDateFormat dateymdhmssssNum = new SimpleDateFormat("yyyyMMddHHmmssSSS");
 private static final SimpleDateFormat subDate = new SimpleDateFormat("yyyy-MM-dd-HH-mm-ss");
 private static final SimpleDateFormat datemdhm = new SimpleDateFormat("MM-dd HH:mm");
 private static final SimpleDateFormat hm = new SimpleDateFormat("HH:mm");

时间格式化