com.hazelcast.map.MapInterceptor Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2013, Hazelcast, Inc. 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 com.hazelcast.map;
import java.io.Serializable;
/**
* MapInterceptor is used to intercept changes to the map, allowing access to the values before and
* after adding it to the map
*
* MapInterceptors are chained when added to the map, which means that when an interceptor is added
* on node initialization it could be added twice. To prevent this make sure to implement the
* hashCode method to return the same value for every instance of the class.
*
*/
public interface MapInterceptor extends Serializable {
/**
* Intercept get operation before returning value.
* Return another object to change the return value of get(..)
* Returning null will cause the get(..) operation return original value,
* namely return null if you do not want to change anything.
*
* Mutations made to value do not affect the stored value. They do affect the returned value.
*
* @param value the original value to be returned as the result of get(..) operation
* @return the new value that will be returned by get(..) operation
*/
Object interceptGet(Object value);
/**
* Called after get(..) operation is completed.
*
* Mutations made to value do not affect the stored value.
*
* @param value the value returned as the result of get(..) operation
*/
void afterGet(Object value);
/**
* Intercept put operation before modifying map data.
* Return the object to be put into the map.
* Returning null will cause the put(..) operation to operate as expected, namely no interception.
* Throwing an exception will cancel the put operation.
*
*
* @param oldValue the value currently in map
* @param newValue the new value to be put
* @return new value after intercept operation
*/
Object interceptPut(Object oldValue, Object newValue);
/**
* Called after put(..) operation is completed.
*
*
* @param value the value returned as the result of put(..) operation
*/
void afterPut(Object value);
/**
* Intercept remove operation before removing the data.
* Return the object to be returned as the result of remove operation.
* Throwing an exception will cancel the remove operation.
*
*
* @param removedValue the existing value to be removed
* @return the value to be returned as the result of remove operation
*/
Object interceptRemove(Object removedValue);
/**
* Called after remove(..) operation is completed.
*
*
* @param value the value returned as the result of remove(..) operation
*/
void afterRemove(Object value);
}