ListAggregator.java

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.storm.s3.aggregator;

import storm.trident.operation.ReducerAggregator;
import storm.trident.tuple.TridentTuple;

import java.util.ArrayList;
import java.util.List;

public class ListAggregator implements ReducerAggregator<List> {

    public ListAggregator() {
    }

    public List init() {
        return new ArrayList();
    }

    public List reduce(List curr, TridentTuple tuple) {
        curr.add(tuple);
        return curr;
    }
}