Java tutorial
//package com.java2s; import java.text.SimpleDateFormat; import java.util.Date; public class Main { public static String millisToStringFilename(long millis, String pattern) { String dateStr = millisToStringDate(millis, pattern); return dateStr.replaceAll("[- :]", "_"); } public static String millisToStringFilename(long millis) { String dateStr = millisToStringDate(millis, "yyyy-MM-dd HH:mm:ss"); return dateStr.replaceAll("[- :]", "_"); } public static String millisToStringDate(long millis) { return millisToStringDate(millis, "yyyy-MM-dd HH:mm:ss"); } public static String millisToStringDate(long millis, String pattern) { SimpleDateFormat format = new SimpleDateFormat(pattern); return format.format(new Date(millis)); } }