| /** |
| * 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 hello; |
| |
| import org.apache.s4.base.Event; |
| import org.apache.s4.core.ProcessingElement; |
| |
| public class HelloPE extends ProcessingElement { |
| |
| // you should define downstream streams here and inject them in the app definition |
| |
| boolean seen = false; |
| |
| /** |
| * This method is called upon a new Event on an incoming stream |
| */ |
| public void onEvent(Event event) { |
| // in this example, we use the default generic Event type, by you can also define your own type |
| System.out.println("Hello " + (seen ? "again " : "") + event.get("name") + "!"); |
| seen = true; |
| } |
| |
| @Override |
| protected void onCreate() { |
| } |
| |
| @Override |
| protected void onRemove() { |
| } |
| |
| } |