NonNullResultsCombiner.java example

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eurekastreams-master
/*
 * Copyright (c) 2010 Lockheed Martin Corporation
 *
 * 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.eurekastreams.server.persistence.mappers.chained;

/**
 * Result combiner that returns one of the results that's not null.
 * 
 * @param <T>
 *            the type of response to handle
 */
public class NonNullResultsCombiner<T> implements ResultsCombinerStrategy<Object, T>
{
    /**
     * Return the first non-null value.
     * 
     * @param inResponse1
     *            the first response to return if not null
     * @param inResponse2
     *            the second response to return if not null
     * @param request
     *            the request, not used.
     * @return inResponse1 if not null, else inResponse2
     */
    public T combine(final PartialMapperResponse<Object, T> inResponse1, final T inResponse2, final Object request)
    {
        return inResponse1.getResponse() != null ? inResponse1.getResponse() : inResponse2;
    }
}