Here you can find the source of join(String[] a1, String[] a2)
static String[] join(String[] a1, String[] a2)
//package com.java2s; /*/* www . jav a 2s . c o m*/ * Copyright (c) 2014, 2016, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ import java.util.ArrayList; import java.util.Arrays; import java.util.List; public class Main { static String[] join(String[] a1, String[] a2) { List<String> result = new ArrayList<>(); result.addAll(Arrays.asList(a1)); result.addAll(Arrays.asList(a2)); return result.toArray(new String[0]); } }