Here you can find the source of concatenate(T[] first, T[] second)
public static <T> T[] concatenate(T[] first, T[] second)
//package com.java2s; import java.util.*; public class Main { /**/*from w w w . j ava 2s . co m*/ * Concatenates two arrays and returns the result */ public static <T> T[] concatenate(T[] first, T[] second) { T[] result = Arrays.copyOf(first, first.length + second.length); System.arraycopy(second, 0, result, first.length, second.length); return result; } }