com.google.common.collect.EnumMultiset Maven / Gradle / Ivy
/*
* Copyright (C) 2007 The Guava Authors
*
* 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 com.google.common.collect;
import static com.google.common.base.Preconditions.checkArgument;
import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.EnumMap;
import java.util.Iterator;
/**
* Multiset implementation backed by an {@link EnumMap}.
*
* See the Guava User Guide article on
* {@code Multiset}.
*
* @author Jared Levy
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible(emulated = true)
public final class EnumMultiset> extends AbstractMapBasedMultiset {
/** Creates an empty {@code EnumMultiset}. */
public static > EnumMultiset create(Class type) {
return new EnumMultiset(type);
}
/**
* Creates a new {@code EnumMultiset} containing the specified elements.
*
* This implementation is highly efficient when {@code elements} is itself a {@link
* Multiset}.
*
* @param elements the elements that the multiset should contain
* @throws IllegalArgumentException if {@code elements} is empty
*/
public static > EnumMultiset create(Iterable elements) {
Iterator iterator = elements.iterator();
checkArgument(iterator.hasNext(), "EnumMultiset constructor passed empty Iterable");
EnumMultiset multiset = new EnumMultiset(iterator.next().getDeclaringClass());
Iterables.addAll(multiset, elements);
return multiset;
}
/**
* Returns a new {@code EnumMultiset} instance containing the given elements. Unlike
* {@link EnumMultiset#create(Iterable)}, this method does not produce an exception on an empty
* iterable.
*
* @since 14.0
*/
public static > EnumMultiset create(Iterable elements, Class type) {
EnumMultiset result = create(type);
Iterables.addAll(result, elements);
return result;
}
private transient Class type;
/** Creates an empty {@code EnumMultiset}. */
private EnumMultiset(Class type) {
super(WellBehavedMap.wrap(new EnumMap(type)));
this.type = type;
}
@GwtIncompatible("java.io.ObjectOutputStream")
private void writeObject(ObjectOutputStream stream) throws IOException {
stream.defaultWriteObject();
stream.writeObject(type);
Serialization.writeMultiset(this, stream);
}
/**
* @serialData the {@code Class} for the enum type, the number of distinct
* elements, the first element, its count, the second element, its
* count, and so on
*/
@GwtIncompatible("java.io.ObjectInputStream")
private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException {
stream.defaultReadObject();
@SuppressWarnings("unchecked") // reading data stored by writeObject
Class localType = (Class) stream.readObject();
type = localType;
setBackingMap(WellBehavedMap.wrap(new EnumMap(type)));
Serialization.populateMultiset(this, stream);
}
@GwtIncompatible("Not needed in emulated source")
private static final long serialVersionUID = 0;
}