Java tutorial
/* * $Id$ * * Janus platform is an open-source multiagent platform. * More details on http://www.janusproject.io * * Copyright (C) 2014 Sebastian RODRIGUEZ, Nicolas GAUD, Stphane GALLAND. * * 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 io.janusproject.util; import com.google.common.collect.Lists; import com.google.common.collect.Maps; import com.google.common.collect.Multimap; import com.google.common.collect.Multiset; import com.google.common.collect.Sets; import java.io.Serializable; import java.util.AbstractCollection; import java.util.AbstractList; import java.util.AbstractMap; import java.util.AbstractSet; import java.util.Collection; import java.util.Iterator; import java.util.LinkedHashSet; import java.util.List; import java.util.Map; import java.util.Map.Entry; import java.util.Set; import java.util.TreeSet; import io.janusproject.services.distributeddata.DMultiMap; import io.janusproject.util.DataViewDelegate.Delegator; /** * A view on a Map that provides the API for the DMultiMap. * * @param <K> - type of the keys. * @param <V> - type of the values. * @author $Author: sgalland$ * @version $FullVersion$ * @mavengroupid $GroupId$ * @mavenartifactid $ArtifactId$ */ public abstract class AbstractDMultiMapView<K, V> extends AbstractMapView<K, V> implements DMultiMap<K, V>, Serializable, Delegator<Multimap<K, V>> { private static final long serialVersionUID = -6970650402150118406L; private final String name; private transient Map<K, Collection<V>> map; /** * @param name - the name of the map. */ public AbstractDMultiMapView(String name) { this.name = name; } @Override public boolean isBackedCollection() { return true; } /** * Wrap the given values into a dedicated view. * <p/> * The replies view may be a {@link SingleKeyValueListView} or * a {@link SingleKeyValueSetView} according to the type of the * given values' collection. * * @param key - the key of the values. * @param values - the values. * @return the wrapper. */ Collection<V> wrapValues(K key, Collection<V> values) { Object backEnd = DataViewDelegate.undelegate(values); if (backEnd instanceof List<?>) { return new SingleKeyValueListView(key, (List<V>) values); } if (backEnd instanceof Set<?>) { return new SingleKeyValueSetView(key, (Set<V>) values); } throw new IllegalStateException("Unsupported type of the backend multimap: " + values.getClass()); //$NON-NLS-1$ } /** * Copy the given values. * <p/> * The replies collection may be a {@link List} or * a {@link Set} according to the type of the * given values' collection. * * @param values - the values. * @return the copy. */ @SuppressWarnings("unchecked") Collection<V> copyValues(Collection<V> values) { Object backEnd = DataViewDelegate.undelegate(values); if (backEnd instanceof List<?>) { return Lists.newArrayList(values); } if (backEnd instanceof TreeSet<?>) { TreeSet<V> c = (TreeSet<V>) backEnd; c = Sets.newTreeSet(c.comparator()); c.addAll(values); return c; } if (backEnd instanceof LinkedHashSet<?>) { return Sets.newLinkedHashSet(values); } if (backEnd instanceof Set<?>) { return Sets.newHashSet(values); } throw new IllegalStateException("Unsupported type of the backend multimap: " + values.getClass()); //$NON-NLS-1$ } @Override public String getName() { return this.name; } @Override public boolean equals(Object obj) { return getDelegatedObject().equals(DataViewDelegate.undelegate(obj)); } @Override public int hashCode() { return getDelegatedObject().hashCode(); } @Override public String toString() { return getDelegatedObject().toString(); } @Override public boolean containsKey(Object key) { return getDelegatedObject().containsKey(key); } @Override public boolean containsValue(Object value) { return getDelegatedObject().containsValue(value); } @Override public boolean containsEntry(Object key, Object value) { return getDelegatedObject().containsEntry(key, value); } @Override public int size() { return getDelegatedObject().size(); } @Override public int valueCount(K key) { Collection<V> values = getDelegatedObject().get(key); if (values != null && !values.isEmpty()) { return values.size(); } return 0; } @Override public boolean isEmpty() { return getDelegatedObject().isEmpty(); } @Override public boolean put(K key, V value) { if (getDelegatedObject().put(key, value)) { fireEntryAdded(key, value); return true; } return false; } @SuppressWarnings("unchecked") @Override public boolean remove(Object key, Object value) { if (getDelegatedObject().remove(key, value)) { fireEntryRemoved((K) key, (V) value); return true; } return false; } @SuppressWarnings("unchecked") @Override public Collection<V> removeAll(Object key) { Collection<V> values = getDelegatedObject().removeAll(key); if (values != null && !values.isEmpty()) { K kkey = (K) key; for (V value : values) { fireEntryRemoved(kkey, value); } } return values; } @Override public boolean putAll(K key, Iterable<? extends V> values) { boolean changed = false; for (V value : values) { if (getDelegatedObject().put(key, value)) { changed = true; fireEntryAdded(key, value); } } return changed; } @Override public boolean putAll(Multimap<? extends K, ? extends V> multimap) { boolean changed = false; for (Entry<? extends K, ? extends V> entry : multimap.entries()) { if (getDelegatedObject().put(entry.getKey(), entry.getValue())) { changed = true; fireEntryAdded(entry.getKey(), entry.getValue()); } } return changed; } @Override public Collection<V> replaceValues(K key, Iterable<? extends V> values) { return getDelegatedObject().replaceValues(key, values); } @Override public void clear() { if (!getDelegatedObject().isEmpty()) { getDelegatedObject().clear(); fireCleared(false); } } @Override public Collection<V> get(K key) { return wrapValues(key, getDelegatedObject().get(key)); } @Override public Set<K> keySet() { return new KeySetView(getDelegatedObject().keySet()); } @Override public Collection<Entry<K, V>> entries() { return new EntryCollectionView(getDelegatedObject().entries()); } @Override public Collection<V> values() { return new ValueCollectionView(getDelegatedObject().entries()); } @Override public Multiset<K> keys() { return new MultisetView<>(this); } @Override public Map<K, Collection<V>> asMap() { if (this.map == null) { this.map = new MapView(getDelegatedObject().asMap()); } return this.map; } /** * A view on the values of specific key in a {@link AbstractDMultiMapView}. * * @author $Author: sgalland$ * @version $FullVersion$ * @mavengroupid $GroupId$ * @mavenartifactid $ArtifactId$ */ protected class SingleKeyValueListView extends AbstractList<V> implements Serializable, Delegator<List<V>> { private static final long serialVersionUID = 4290615787745160981L; private final K key; private final List<V> values; /** * @param key - the key of the values. * @param values - the values. */ public SingleKeyValueListView(K key, List<V> values) { this.key = key; this.values = values; } @Override public List<V> getDelegatedObject() { return this.values; } @Override public boolean equals(Object obj) { return getDelegatedObject().equals(DataViewDelegate.undelegate(obj)); } @Override public int hashCode() { return getDelegatedObject().hashCode(); } @Override public String toString() { return getDelegatedObject().toString(); } @Override public int size() { return this.values.size(); } @Override public V get(int index) { return this.values.get(index); } @Override public Iterator<V> iterator() { return new ValueIterator(this.values.iterator()); } @Override public boolean add(V e) { if (this.values.add(e)) { fireEntryAdded(this.key, e); return true; } return false; } @Override public void clear() { AbstractDMultiMapView.this.removeAll(this.key); } /** * @author $Author: sgalland$ * @version $FullVersion$ * @mavengroupid $GroupId$ * @mavenartifactid $ArtifactId$ */ private class ValueIterator implements Iterator<V> { private final Iterator<V> iterator; private V value; public ValueIterator(Iterator<V> iterator) { this.iterator = iterator; } @Override public boolean hasNext() { return this.iterator.hasNext(); } @Override public V next() { this.value = this.iterator.next(); return this.value; } @SuppressWarnings("synthetic-access") @Override public void remove() { this.iterator.remove(); fireEntryRemoved(SingleKeyValueListView.this.key, this.value); } } } /** * A view on the values of specific key in a {@link AbstractDMultiMapView}. * * @author $Author: sgalland$ * @version $FullVersion$ * @mavengroupid $GroupId$ * @mavenartifactid $ArtifactId$ */ protected class SingleKeyValueSetView extends AbstractSet<V> implements Serializable, Delegator<Set<V>> { private static final long serialVersionUID = 4290615787745160981L; private final K key; private final Set<V> values; /** * @param key - the key of the values. * @param values - the values. */ public SingleKeyValueSetView(K key, Set<V> values) { this.key = key; this.values = values; } @Override public Set<V> getDelegatedObject() { return this.values; } @Override public boolean equals(Object obj) { return getDelegatedObject().equals(DataViewDelegate.undelegate(obj)); } @Override public int hashCode() { return getDelegatedObject().hashCode(); } @Override public String toString() { return getDelegatedObject().toString(); } @Override public int size() { return this.values.size(); } @Override public Iterator<V> iterator() { return new ValueIterator(this.values.iterator()); } @Override public boolean add(V e) { if (this.values.add(e)) { fireEntryAdded(this.key, e); return true; } return false; } @Override public void clear() { AbstractDMultiMapView.this.removeAll(this.key); } /** * @author $Author: sgalland$ * @version $FullVersion$ * @mavengroupid $GroupId$ * @mavenartifactid $ArtifactId$ */ private class ValueIterator implements Iterator<V> { private final Iterator<V> iterator; private V value; public ValueIterator(Iterator<V> iterator) { this.iterator = iterator; } @Override public boolean hasNext() { return this.iterator.hasNext(); } @Override public V next() { this.value = this.iterator.next(); return this.value; } @SuppressWarnings("synthetic-access") @Override public void remove() { this.iterator.remove(); fireEntryRemoved(SingleKeyValueSetView.this.key, this.value); } } } /** * A view on the keys in a {@link AbstractDMultiMapView}. * * @author $Author: sgalland$ * @version $FullVersion$ * @mavengroupid $GroupId$ * @mavenartifactid $ArtifactId$ */ protected class KeySetView extends AbstractSet<K> implements Serializable, Delegator<Set<K>> { private static final long serialVersionUID = -5008029594376258921L; private final Set<K> keys; /** * @param keys - the keys in the multimap. */ public KeySetView(Set<K> keys) { this.keys = keys; } @Override public Set<K> getDelegatedObject() { return this.keys; } @Override public boolean equals(Object obj) { return getDelegatedObject().equals(DataViewDelegate.undelegate(obj)); } @Override public int hashCode() { return getDelegatedObject().hashCode(); } @Override public String toString() { return getDelegatedObject().toString(); } @Override public int size() { return this.keys.size(); } @Override public Iterator<K> iterator() { return new KeyIterator(this.keys.iterator()); } /** * @author $Author: sgalland$ * @version $FullVersion$ * @mavengroupid $GroupId$ * @mavenartifactid $ArtifactId$ */ private class KeyIterator implements Iterator<K> { private final Iterator<K> iterator; private K key; public KeyIterator(Iterator<K> iterator) { this.iterator = iterator; } @Override public boolean hasNext() { return this.iterator.hasNext(); } /** * {@inheritDoc} */ @Override public K next() { this.key = this.iterator.next(); return this.key; } @SuppressWarnings("unchecked") @Override public void remove() { Collection<V> oldValues = get(this.key); V[] tab = (V[]) new Object[oldValues.size()]; oldValues.toArray(tab); this.iterator.remove(); for (V value : tab) { fireEntryRemoved(this.key, value); } } } } /** * A view on the entries in a {@link AbstractDMultiMapView}. * * @author $Author: sgalland$ * @version $FullVersion$ * @mavengroupid $GroupId$ * @mavenartifactid $ArtifactId$ */ protected class EntryCollectionView extends AbstractCollection<Entry<K, V>> implements Serializable, Delegator<Collection<Entry<K, V>>> { private static final long serialVersionUID = 3746778947439539504L; private final Collection<Entry<K, V>> entries; /** * @param entries - the entries in the multimap. */ public EntryCollectionView(Collection<Entry<K, V>> entries) { this.entries = entries; } @Override public Collection<Entry<K, V>> getDelegatedObject() { return AbstractDMultiMapView.this.getDelegatedObject().entries(); } @Override public boolean equals(Object obj) { return getDelegatedObject().equals(DataViewDelegate.undelegate(obj)); } @Override public int hashCode() { return getDelegatedObject().hashCode(); } @Override public String toString() { return getDelegatedObject().toString(); } @Override public int size() { return this.entries.size(); } @Override public Iterator<Entry<K, V>> iterator() { return new EntryIterator(this.entries.iterator()); } @Override public boolean add(Entry<K, V> e) { if (this.entries.add(e)) { fireEntryAdded(e.getKey(), e.getValue()); return true; } return false; } /** * @author $Author: sgalland$ * @version $FullVersion$ * @mavengroupid $GroupId$ * @mavenartifactid $ArtifactId$ */ private class EntryIterator implements Iterator<Entry<K, V>> { private final Iterator<Entry<K, V>> iterator; private Entry<K, V> entry; public EntryIterator(Iterator<Entry<K, V>> iterator) { this.iterator = iterator; } @Override public boolean hasNext() { return this.iterator.hasNext(); } @Override public Entry<K, V> next() { this.entry = this.iterator.next(); return this.entry; } @Override public void remove() { this.iterator.remove(); fireEntryRemoved(this.entry.getKey(), this.entry.getValue()); } } } /** * A view on all the values in a {@link AbstractDMultiMapView}. * * @author $Author: sgalland$ * @version $FullVersion$ * @mavengroupid $GroupId$ * @mavenartifactid $ArtifactId$ */ protected class ValueCollectionView extends AbstractCollection<V> implements Serializable, Delegator<Collection<V>> { private static final long serialVersionUID = -1288962742301549934L; private final Collection<Entry<K, V>> entries; /** * @param entries - the entries in the multimap. */ public ValueCollectionView(Collection<Entry<K, V>> entries) { this.entries = entries; } @Override public Collection<V> getDelegatedObject() { return AbstractDMultiMapView.this.getDelegatedObject().values(); } @Override public boolean equals(Object obj) { return getDelegatedObject().equals(DataViewDelegate.undelegate(obj)); } @Override public int hashCode() { return getDelegatedObject().hashCode(); } @Override public String toString() { return getDelegatedObject().toString(); } @Override public void clear() { AbstractDMultiMapView.this.clear(); } @Override public int size() { return this.entries.size(); } @Override public Iterator<V> iterator() { return new ValueIterator(this.entries.iterator()); } /** * @author $Author: sgalland$ * @version $FullVersion$ * @mavengroupid $GroupId$ * @mavenartifactid $ArtifactId$ */ private class ValueIterator implements Iterator<V> { private final Iterator<Entry<K, V>> iterator; private Entry<K, V> entry; public ValueIterator(Iterator<Entry<K, V>> iterator) { this.iterator = iterator; } @Override public boolean hasNext() { return this.iterator.hasNext(); } @Override public V next() { this.entry = this.iterator.next(); return this.entry.getValue(); } @Override public void remove() { this.iterator.remove(); fireEntryRemoved(this.entry.getKey(), this.entry.getValue()); } } } /** * Map view on a {@link AbstractDMultiMapView}. * * @author $Author: sgalland$ * @version $FullVersion$ * @mavengroupid $GroupId$ * @mavenartifactid $ArtifactId$ */ protected class MapView extends AbstractMap<K, Collection<V>> implements Delegator<Map<K, Collection<V>>> { private final Map<K, Collection<V>> backedMap; /** * @param backedMap - the backed map. */ public MapView(Map<K, Collection<V>> backedMap) { this.backedMap = backedMap; } @Override public Map<K, Collection<V>> getDelegatedObject() { return this.backedMap; } @Override public boolean equals(Object obj) { return this.backedMap.equals(obj); } @Override public int hashCode() { return this.backedMap.hashCode(); } @Override public String toString() { return this.backedMap.toString(); } @Override public Set<Entry<K, Collection<V>>> entrySet() { return new EntrySet(this.backedMap.entrySet()); } @SuppressWarnings("unchecked") @Override public Collection<V> remove(Object key) { Collection<V> collection = this.backedMap.remove(key); if (collection == null) { return null; } Collection<V> output = copyValues(collection); collection.clear(); for (V value : output) { fireEntryRemoved((K) key, value); } return output; } @SuppressWarnings("unchecked") @Override public Collection<V> get(Object key) { Collection<V> collection = this.backedMap.get(key); if (collection == null) { return null; } return wrapValues((K) key, collection); } @Override public void clear() { AbstractDMultiMapView.this.clear(); } @Override public Set<K> keySet() { return AbstractDMultiMapView.this.keySet(); } /** * @author $Author: sgalland$ * @version $FullVersion$ * @mavengroupid $GroupId$ * @mavenartifactid $ArtifactId$ */ private class EntrySet extends AbstractSet<Entry<K, Collection<V>>> { private final Set<Entry<K, Collection<V>>> backedSet; /** * @param backedSet - the backed set. */ public EntrySet(Set<Entry<K, Collection<V>>> backedSet) { this.backedSet = backedSet; } @Override public Iterator<java.util.Map.Entry<K, Collection<V>>> iterator() { return new EntryIterator(this.backedSet.iterator()); } @Override public int size() { return this.backedSet.size(); } /** * @author $Author: sgalland$ * @version $FullVersion$ * @mavengroupid $GroupId$ * @mavenartifactid $ArtifactId$ */ private class EntryIterator implements Iterator<Entry<K, Collection<V>>> { private final Iterator<Entry<K, Collection<V>>> iterator; private Entry<K, Collection<V>> entry; /** * @param iterator - the iterator. */ public EntryIterator(Iterator<Entry<K, Collection<V>>> iterator) { this.iterator = iterator; } @Override public boolean hasNext() { return this.iterator.hasNext(); } @Override public Entry<K, Collection<V>> next() { this.entry = this.iterator.next(); Collection<V> wrappedValues = wrapValues(this.entry.getKey(), this.entry.getValue()); return Maps.immutableEntry(this.entry.getKey(), wrappedValues); } @Override public void remove() { if (this.entry == null) { throw new IllegalStateException(); } Collection<V> originalCollection = this.entry.getValue(); Collection<V> oldValues = Lists.newArrayList(originalCollection); // The remove is clearing the backend collection this.iterator.remove(); K key = this.entry.getKey(); for (V value : oldValues) { fireEntryRemoved(key, value); } this.entry = null; } } } } }