Here you can find the source of join(final String left, final String right)
public static String join(final String left, final String right)
//package com.java2s; /*//from w w w .j av a2 s.co m * Copyright 2016 Luk? Petrovick? * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import java.util.StringJoiner; public class Main { public static String join(final String left, final String right) { return new StringJoiner(".").add(left).add(right).toString(); } }