1/* 2 * Copyright (C) 2009 The Guava Authors 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 17package com.google.common.collect; 18 19import com.google.common.annotations.GwtCompatible; 20import com.google.common.annotations.GwtIncompatible; 21 22import java.io.InvalidObjectException; 23import java.io.ObjectInputStream; 24import java.io.Serializable; 25 26/** 27 * List returned by {@link ImmutableCollection#asList} that delegates {@code contains} checks 28 * to the backing collection. 29 * 30 * @author Jared Levy 31 * @author Louis Wasserman 32 */ 33@GwtCompatible(serializable = true, emulated = true) 34@SuppressWarnings("serial") 35abstract class ImmutableAsList<E> extends ImmutableList<E> { 36 abstract ImmutableCollection<E> delegateCollection(); 37 38 @Override public boolean contains(Object target) { 39 // The collection's contains() is at least as fast as ImmutableList's 40 // and is often faster. 41 return delegateCollection().contains(target); 42 } 43 44 @Override 45 public int size() { 46 return delegateCollection().size(); 47 } 48 49 @Override 50 public boolean isEmpty() { 51 return delegateCollection().isEmpty(); 52 } 53 54 @Override 55 boolean isPartialView() { 56 return delegateCollection().isPartialView(); 57 } 58 59 /** 60 * Serialized form that leads to the same performance as the original list. 61 */ 62 @GwtIncompatible("serialization") 63 static class SerializedForm implements Serializable { 64 final ImmutableCollection<?> collection; 65 SerializedForm(ImmutableCollection<?> collection) { 66 this.collection = collection; 67 } 68 Object readResolve() { 69 return collection.asList(); 70 } 71 private static final long serialVersionUID = 0; 72 } 73 74 @GwtIncompatible("serialization") 75 private void readObject(ObjectInputStream stream) 76 throws InvalidObjectException { 77 throw new InvalidObjectException("Use SerializedForm"); 78 } 79 80 @GwtIncompatible("serialization") 81 @Override Object writeReplace() { 82 return new SerializedForm(delegateCollection()); 83 } 84} 85