subprojects/s4-example/src/main/java/org/apache/s4/example/counter/UserIDKeyFinder.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.s4.example.counter;

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

import org.apache.s4.base.KeyFinder;
public class UserIDKeyFinder implements KeyFinder<UserEvent> {

    public List<String> get(UserEvent event) {

        List<String> results = new ArrayList<String>();

        /* Retrieve the user ID and add it to the list. */
        results.add(event.getUserID());

        return results;
    }
}