Java tutorial
/* * Copyright 2015 MovingBlocks * * 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. */ package org.terasology.util; import com.google.common.collect.ImmutableList; import com.google.common.collect.ImmutableSet; import java.util.Arrays; /** * Utility class for methods to help with the use of vararg parameters * * @author Immortius */ public final class Varargs { private Varargs() { } /** * Combines a single value and array into an immutable set. Iteration of the set maintains the order of the items. * This is intended to aid methods using the mandatory-first optional-additional varargs trick. * * @param first The first, single value * @param additional Any additional values * @param <T> The type of the items * @return A set of the combined values */ @SafeVarargs public static <T> ImmutableSet<T> combineToSet(T first, T... additional) { ImmutableSet.Builder<T> builder = ImmutableSet.builder(); builder.add(first); builder.addAll(Arrays.asList(additional)); return builder.build(); } /** * Combines a single value and array into an immutable list. * This is intended to aid methods using the mandatory-first optional-additional varargs trick. * * @param first The first, single value * @param additional Any additional values * @param <T> The type of the items * @return A set of the combined values */ @SafeVarargs public static <T> ImmutableList<T> combineToList(T first, T... additional) { ImmutableList.Builder<T> builder = ImmutableList.builder(); builder.add(first); builder.addAll(Arrays.asList(additional)); return builder.build(); } }