Here you can find the source of format(Long date, String pattern)
public static String format(Long date, String pattern)
//package com.java2s; import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.Date; public class Main { private static final SimpleDateFormat DB_FORMAT = new SimpleDateFormat("yyyyMMddHHmmss"); public static Long format(Date date) { return Long.parseLong(DB_FORMAT.format(date)); }/*from w w w . j a va 2 s .c o m*/ public static String format(Long date, String pattern) { try { Date d = DB_FORMAT.parse(String.valueOf(date)); return format(d, pattern); } catch (ParseException e) { return ""; } } public static String format(Date date, String pattern) { return new SimpleDateFormat(pattern).format(date); } public static Date parse(Long date) { try { return DB_FORMAT.parse(String.valueOf(date)); } catch (ParseException e) { return null; } } }