|
Java example source code file (AbstractSortedMultiset.java)
This example Java source code file (AbstractSortedMultiset.java) is included in the alvinalexander.com
"Java Source Code
Warehouse" project. The intent of this project is to help you "Learn
Java by Example" TM.
Learn more about this Java project at its project page.
The AbstractSortedMultiset.java Java example source code
/*
* Copyright (C) 2011 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.checkNotNull;
import com.google.common.annotations.GwtCompatible;
import com.google.j2objc.annotations.WeakOuter;
import java.util.Comparator;
import java.util.Iterator;
import java.util.NavigableSet;
import javax.annotation.Nullable;
/**
* This class provides a skeletal implementation of the {@link SortedMultiset} interface.
*
* <p>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 Louis Wasserman
*/
@GwtCompatible(emulated = true)
abstract class AbstractSortedMultiset<E> extends AbstractMultiset implements SortedMultiset {
@GwtTransient final Comparator<? super E> comparator;
// needed for serialization
@SuppressWarnings("unchecked")
AbstractSortedMultiset() {
this((Comparator) Ordering.natural());
}
AbstractSortedMultiset(Comparator<? super E> comparator) {
this.comparator = checkNotNull(comparator);
}
@Override
public NavigableSet<E> elementSet() {
return (NavigableSet<E>) super.elementSet();
}
@Override
NavigableSet<E> createElementSet() {
return new SortedMultisets.NavigableElementSet<E>(this);
}
@Override
public Comparator<? super E> comparator() {
return comparator;
}
@Override
public Entry<E> firstEntry() {
Iterator<Entry entryIterator = entryIterator();
return entryIterator.hasNext() ? entryIterator.next() : null;
}
@Override
public Entry<E> lastEntry() {
Iterator<Entry entryIterator = descendingEntryIterator();
return entryIterator.hasNext() ? entryIterator.next() : null;
}
@Override
public Entry<E> pollFirstEntry() {
Iterator<Entry entryIterator = entryIterator();
if (entryIterator.hasNext()) {
Entry<E> result = entryIterator.next();
result = Multisets.immutableEntry(result.getElement(), result.getCount());
entryIterator.remove();
return result;
}
return null;
}
@Override
public Entry<E> pollLastEntry() {
Iterator<Entry entryIterator = descendingEntryIterator();
if (entryIterator.hasNext()) {
Entry<E> result = entryIterator.next();
result = Multisets.immutableEntry(result.getElement(), result.getCount());
entryIterator.remove();
return result;
}
return null;
}
@Override
public SortedMultiset<E> subMultiset(
@Nullable E fromElement,
BoundType fromBoundType,
@Nullable E toElement,
BoundType toBoundType) {
// These are checked elsewhere, but NullPointerTester wants them checked eagerly.
checkNotNull(fromBoundType);
checkNotNull(toBoundType);
return tailMultiset(fromElement, fromBoundType).headMultiset(toElement, toBoundType);
}
abstract Iterator<Entry descendingEntryIterator();
Iterator<E> descendingIterator() {
return Multisets.iteratorImpl(descendingMultiset());
}
private transient SortedMultiset<E> descendingMultiset;
@Override
public SortedMultiset<E> descendingMultiset() {
SortedMultiset<E> result = descendingMultiset;
return (result == null) ? descendingMultiset = createDescendingMultiset() : result;
}
SortedMultiset<E> createDescendingMultiset() {
@WeakOuter
class DescendingMultisetImpl extends DescendingMultiset<E> {
@Override
SortedMultiset<E> forwardMultiset() {
return AbstractSortedMultiset.this;
}
@Override
Iterator<Entry entryIterator() {
return descendingEntryIterator();
}
@Override
public Iterator<E> iterator() {
return descendingIterator();
}
}
return new DescendingMultisetImpl();
}
}
Other Java examples (source code examples)
Here is a short list of links related to this Java AbstractSortedMultiset.java source code file:
|