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'databene commons' is an open source Java library by Volker Bergmann.
It provides extensions to the Java core library by utility classes, abstract concepts
and concrete implementations.
/*
* Copyright (C) 2004-2015 Volker Bergmann ([email protected]).
* All rights reserved.
*
* 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 org.databene.commons.accessor;
import org.databene.commons.Accessor;
import org.databene.commons.NullSafeComparator;
import java.util.Map;
/**
* Accesses Values from a Map.
* Created: 11.03.2006 12:39:07
* @param the object type to access
* @param the key type
* @param the the value type
* @author Volker Bergmann
*/
public class MapAccessor, K, V> implements Accessor {
/**
* the key of the object to look up; null is supported.
*/
private K key;
public MapAccessor(K key) {
this.key = key;
}
// Accessor interface ----------------------------------------------------------------------------------------------
@Override
public V getValue(C item) {
return item.get(key);
}
// java.lang.Object overrides --------------------------------------------------------------------------------------
@SuppressWarnings("rawtypes")
@Override
public boolean equals(Object o) {
if (this == o)
return true;
if (o == null || getClass() != o.getClass())
return false;
final MapAccessor that = (MapAccessor) o;
return NullSafeComparator.equals(this.key, that.key);
}
@Override
public int hashCode() {
return (key != null ? key.hashCode() : 0);
}
}