Java tutorial
//package com.java2s; /******************************************************************************* * Copyright (c) 2015-2018 Skymind, Inc. * * This program and the accompanying materials are made available under the * terms of the Apache License, Version 2.0 which is available at * https://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. * * SPDX-License-Identifier: Apache-2.0 ******************************************************************************/ import java.util.ArrayList; import java.util.Collection; import java.util.HashSet; import java.util.List; public class Main { /** * Returns a list containing only unique values in a collection */ public static <T> List<T> getUnique(Collection<T> collection) { HashSet<T> set = new HashSet<>(); List<T> out = new ArrayList<>(); for (T t : collection) { if (!set.contains(t)) { out.add(t); set.add(t); } } return out; } }