1 /* 2 * Copyright (C) 2011 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 package com.android.tradefed.util; 17 18 import com.android.tradefed.build.BuildSerializedVersion; 19 20 import java.util.Collection; 21 22 /** 23 * A {@link MultiMap} that ensures unique values for each key. 24 * <p/> 25 * Attempts to insert a duplicate value will be ignored 26 * @param <K> 27 */ 28 public class UniqueMultiMap<K, V> extends MultiMap<K, V> { 29 30 private static final long serialVersionUID = BuildSerializedVersion.VERSION; 31 32 @Override 33 public V put(K key, V value) { 34 Collection<V> values = get(key); 35 if (values != null && values.contains(value)) { 36 return null; 37 } 38 return super.put(key, value); 39 } 40 } 41
