Here you can find the source of getBirthday(String age)
public static String getBirthday(String age)
//package com.java2s; //License from project: Apache License import java.text.SimpleDateFormat; import java.util.Calendar; import java.util.Date; public class Main { private static String defaultDatePattern = "yyyy-MM-dd"; public static String getBirthday(String age) { Calendar c = Calendar.getInstance(); c.add(Calendar.YEAR, -Integer.parseInt(age)); SimpleDateFormat format = new SimpleDateFormat(defaultDatePattern); return format.format(c.getTime()); }//from w w w . j a va 2 s.c o m public static String format(Date date) { return date == null ? "" : format(date, getDatePattern()); } public static String format(Date date, String pattern) { return date == null ? "" : new SimpleDateFormat(pattern) .format(date); } public static String getDatePattern() { return defaultDatePattern; } }