com.c123.billbuddy.dal.Top5MerchantFeeAmountReducer.java Source code

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Here is the source code for com.c123.billbuddy.dal.Top5MerchantFeeAmountReducer.java

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/***************************************************************************
****
 * Copyright (c) 2013 GigaSpaces Technologies Ltd. and 123Completed Ltd. 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.c123.billbuddy.dal;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.openspaces.remoting.RemoteResultReducer;
import org.openspaces.remoting.SpaceRemotingInvocation;
import org.openspaces.remoting.SpaceRemotingResult;

import com.c123.billbuddy.model.Merchant;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

/** 
 *   {@link RemoteResultReducer} object used to reduce the results
 *   returned from the space.
 * 
 * @author 123Completed
 */

public class Top5MerchantFeeAmountReducer implements RemoteResultReducer<Merchant[], Merchant[]> {

    private final Log log = LogFactory.getLog(Top5MerchantFeeAmountReducer.class);

    public Merchant[] reduce(SpaceRemotingResult<Merchant[]>[] results, SpaceRemotingInvocation remotingInvocation)
            throws Exception {

        log.info("Starting Top5MerchantFeeAmountReducer");

        List<Merchant> merchants = new ArrayList<Merchant>();

        // Each result is an array of events. Each result is from a single partition.        
        for (SpaceRemotingResult<Merchant[]> result : results) {
            if (result.getException() != null) {
                // just log the fact that there was an exception
                log.error("Executor Remoting Exception [" + result.getException() + "]");

                continue;
            }
            Collections.addAll(merchants, result.getResult());
        }

        Collections.sort(merchants, new Comparator<Merchant>() {
            public int compare(Merchant p1, Merchant p2) {
                return p2.getFeeAmount().compareTo(p1.getFeeAmount());
            }
        });

        // If the number of results needed is less than the number of events that were reduced, then
        // return a sublist. Otherwise, return the entire list of events.
        Merchant[] top5Merchant;
        if (merchants.size() < 5) {
            top5Merchant = new Merchant[merchants.size()];
            merchants.toArray(top5Merchant);
        } else {
            top5Merchant = new Merchant[5];
            merchants.subList(0, 5).toArray(top5Merchant);
        }
        return top5Merchant;
    }

}