Here you can find the source of join(T[] a, T[] b)
public static <T> T[] join(T[] a, T[] b)
//package com.java2s; //License from project: Open Source License import java.util.*; public class Main { /**/*from w ww . j a v a 2 s .c o m*/ * join two arrays together */ public static <T> T[] join(T[] a, T[] b) { T[] x = Arrays.copyOf(a, a.length + b.length); for (int n = 0; n < b.length; n++) { x[a.length + n] = b[n]; } return x; } }