/*
* Copyright (c) 2008-2017, 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.projection;
import java.io.Serializable;
/**
* Enables transforming object into other objects.
* Exemplary usage scenario is the project() method of the {@link com.hazelcast.core.IMap}
* <p>
* Only 1:1 transformations allowed. Use an Aggregator to perform N:1 or N:M aggregations.
* <p>
* <pre>
* <code>
* IMap<String, Employee> employees = instance.getMap("employees");
*
* Collection<String> names = employees.project(new Projection<Map.Entry<String,Employee>,String>(){
* @Override
* public String transform(Map.Entry<String, Employee>entry){
* return entry.getValue().getName();
* }
* });
* </code>
* </pre>
*
* @param <I> input type
* @param <O> output type
* @since 3.8
*/
public abstract class Projection<I, O> implements Serializable {
/**
* Transforms the input object into the output object.
*
* @param input object.
* @return the output object.
*/
public abstract O transform(I input);
}