Here you can find the source of nvl(S obj, U nullObject)
public static <T, S extends T, U extends T> T nvl(S obj, U nullObject)
//package com.java2s; public class Main { public static <T, S extends T, U extends T> T nvl(S obj, U nullObject) { if (obj != null) { return obj; }/*from w ww. j av a2s . com*/ return nullObject; } }