Here you can find the source of getLastOfYear(Timestamp t1)
public static Timestamp getLastOfYear(Timestamp t1)
//package com.java2s; import java.sql.Timestamp; import java.util.Calendar; import java.util.GregorianCalendar; public class Main { public static Timestamp getLastOfYear(Timestamp t1) { Calendar a = new GregorianCalendar(); a.setTime(t1);/* w w w .j a v a 2 s . c o m*/ a.set(Calendar.MONTH, 11); a.set(Calendar.DATE, 1);// ???????????12?????? a.roll(Calendar.DATE, -1);// ??????????????????????? return new Timestamp(a.getTimeInMillis()); } }