CounterPE.java

/*
 * Copyright (c) 2011 Yahoo! 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. See accompanying LICENSE file. 
 */
package org.apache.s4.example.counter;

import org.apache.s4.base.Event;
import org.apache.s4.core.App;
import org.apache.s4.core.ProcessingElement;
import org.apache.s4.core.Stream;

public class CounterPE extends ProcessingElement {

    private Stream<CountEvent>[] countStream;

    public CounterPE(App app) {
        super(app);
    }

    public Stream<CountEvent>[] getCountStream() {
        return countStream;
    }

    public void setCountStream(Stream<CountEvent>... countStream) {
        this.countStream = countStream;
    }

    private long counter = 0;

    public void onEvent(Event event) {

        counter += 1;
    }

    public void onTrigger(Event event) {

        CountEvent countEvent = new CountEvent(getId(), counter);
        emit(countEvent, countStream);
    }

    @Override
    protected void onCreate() {

    }

    @Override
    protected void onRemove() {

    }
}