com.google.common.reflect.MutableTypeToInstanceMap Maven / Gradle / Ivy
/*
* Copyright (C) 2012 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.reflect;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.Beta;
import com.google.common.base.Function;
import com.google.common.collect.ForwardingMap;
import com.google.common.collect.ForwardingMapEntry;
import com.google.common.collect.ForwardingSet;
import com.google.common.collect.Iterators;
import com.google.common.collect.Maps;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import javax.annotation.Nullable;
/**
* A mutable type-to-instance map.
* See also {@link ImmutableTypeToInstanceMap}.
*
* @author Ben Yu
* @since 13.0
*/
@Beta
public final class MutableTypeToInstanceMap extends ForwardingMap, B>
implements TypeToInstanceMap {
private final Map, B> backingMap = Maps.newHashMap();
@Nullable
@Override
public T getInstance(Class type) {
return trustedGet(TypeToken.of(type));
}
@Nullable
@Override
public T putInstance(Class type, @Nullable T value) {
return trustedPut(TypeToken.of(type), value);
}
@Nullable
@Override
public T getInstance(TypeToken type) {
return trustedGet(type.rejectTypeVariables());
}
@Nullable
@Override
public T putInstance(TypeToken type, @Nullable T value) {
return trustedPut(type.rejectTypeVariables(), value);
}
/** Not supported. Use {@link #putInstance} instead. */
@Override public B put(TypeToken key, B value) {
throw new UnsupportedOperationException("Please use putInstance() instead.");
}
/** Not supported. Use {@link #putInstance} instead. */
@Override public void putAll(Map, ? extends B> map) {
throw new UnsupportedOperationException("Please use putInstance() instead.");
}
@Override public Set, B>> entrySet() {
return UnmodifiableEntry.transformEntries(super.entrySet());
}
@Override protected Map, B> delegate() {
return backingMap;
}
@SuppressWarnings("unchecked") // value could not get in if not a T
@Nullable
private T trustedPut(TypeToken type, @Nullable T value) {
return (T) backingMap.put(type, value);
}
@SuppressWarnings("unchecked") // value could not get in if not a T
@Nullable
private T trustedGet(TypeToken type) {
return (T) backingMap.get(type);
}
private static final class UnmodifiableEntry extends ForwardingMapEntry {
private final Entry delegate;
static Set> transformEntries(final Set> entries) {
return new ForwardingSet>() {
@Override protected Set> delegate() {
return entries;
}
@Override public Iterator> iterator() {
return UnmodifiableEntry.transformEntries(super.iterator());
}
@Override public Object[] toArray() {
return standardToArray();
}
@Override public T[] toArray(T[] array) {
return standardToArray(array);
}
};
}
private static Iterator> transformEntries(Iterator> entries) {
return Iterators.transform(entries, new Function, Entry>() {
@Override public Entry apply(Entry entry) {
return new UnmodifiableEntry(entry);
}
});
}
private UnmodifiableEntry(java.util.Map.Entry delegate) {
this.delegate = checkNotNull(delegate);
}
@Override protected Entry delegate() {
return delegate;
}
@Override public V setValue(V value) {
throw new UnsupportedOperationException();
}
}
}