/* * 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.collect.Multisets.setCountImpl; import com.google.common.annotations.GwtCompatible; import com.google.common.base.Objects; import java.util.AbstractCollection; import java.util.Collection; import java.util.Iterator; import java.util.Set; import javax.annotation.Nullable; /** * This class provides a skeletal implementation of the {@link Multiset} * interface. A new multiset implementation can be created easily by extending * this class and implementing the {@link Multiset#entrySet()} method, plus * optionally overriding {@link #add(Object, int)} and * {@link #remove(Object, int)} to enable modifications to the multiset. * *
The {@link #count} and {@link #size} implementations all iterate across
* the set returned by {@link Multiset#entrySet()}, as do many methods acting on
* the set returned by {@link #elementSet()}. Override those methods for better
* performance.
*
* @author Kevin Bourrillion
* @author Louis Wasserman
*/
@GwtCompatible
abstract class AbstractMultiset This implementation is highly efficient when {@code elementsToAdd}
* is itself a {@link Multiset}.
*/
@Override public boolean addAll(Collection extends E> elementsToAdd) {
return Multisets.addAllImpl(this, elementsToAdd);
}
@Override public boolean removeAll(Collection> elementsToRemove) {
return Multisets.removeAllImpl(this, elementsToRemove);
}
@Override public boolean retainAll(Collection> elementsToRetain) {
return Multisets.retainAllImpl(this, elementsToRetain);
}
@Override public void clear() {
Iterators.clear(entryIterator());
}
// Views
private transient Set This implementation returns {@code true} if {@code object} is a multiset
* of the same size and if, for each element, the two multisets have the same
* count.
*/
@Override public boolean equals(@Nullable Object object) {
return Multisets.equalsImpl(this, object);
}
/**
* {@inheritDoc}
*
* This implementation returns the hash code of {@link
* Multiset#entrySet()}.
*/
@Override public int hashCode() {
return entrySet().hashCode();
}
/**
* {@inheritDoc}
*
* This implementation returns the result of invoking {@code toString} on
* {@link Multiset#entrySet()}.
*/
@Override public String toString() {
return entrySet().toString();
}
}