com.googlecode.ehcache.annotations.key.ListCacheKeyGenerator Maven / Gradle / Ivy
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Provides a simple model for integrating Ehcache in a Spring project via annotations.
/**
* Copyright 2010 Nicholas Blair, Eric Dalquist
*
* 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.googlecode.ehcache.annotations.key;
import java.io.Serializable;
import java.lang.reflect.Array;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
/**
* This key generator is a good option when you want to be 100% sure that two sets of method invocation arguments
* are the same. It does depend on all arguments correctly implementing the hashCode and equals methods. All of
* the objects involved in the invocation arguments are put into {@link List}s and arrays are converted to
* {@link List}s to provide better equals and hashCode behavior.
*
*
*
* Pros
* Cons
*
*
*
* 100% assurance that generated keys will never collide.
*
*
* All method arguments must be completely {@link Serializable} if disk storage or any replication
* operations will be used. A {@link ClassCastException} may be thrown if any argument does not
* implement {@link Serializable}.
*
*
*
*
*
*
* Each time the key is compared using equals or has its hash generated via hashCode all arguments will
* be visited and have their equals and hashCode methods called. This results in a higher expense after
* key generation each time the key is inspected.
*
*
*
*
* @author Eric Dalquist
* @version $Revision: 326 $
*/
public class ListCacheKeyGenerator extends AbstractCacheKeyGenerator> {
/**
* Name of the bean this generator is registered under using the default constructor.
*/
public static final String DEFAULT_BEAN_NAME = "com.googlecode.ehcache.annotations.key.ListCacheKeyGenerator.DEFAULT_BEAN_NAME";
/**
* @see AbstractCacheKeyGenerator#AbstractCacheKeyGenerator()
*/
public ListCacheKeyGenerator() {
}
/**
* @see AbstractCacheKeyGenerator#AbstractCacheKeyGenerator(boolean, boolean)
*/
public ListCacheKeyGenerator(boolean includeMethod, boolean includeParameterTypes) {
super(includeMethod, includeParameterTypes);
}
@Override
public ReadOnlyList generateKey(Object... data) {
final ArrayList keyList = new ArrayList(data.length);
for (final Object arg : data) {
keyList.add(this.arrayCheck((Serializable)arg));
}
return new ReadOnlyList(keyList);
}
protected Serializable arrayCheck(Serializable object) {
if (object == null || !register(object)) {
//Return null in place of the actual hash code in the case of a circular reference
return null;
}
try {
final Class c = object.getClass();
if (!c.isArray()) {
return object;
}
final int length = Array.getLength(object);
final ArrayList