| /* |
| * |
| * 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.qpid.proton.example.reactor; |
| |
| import java.io.IOException; |
| |
| import org.apache.qpid.proton.Proton; |
| import org.apache.qpid.proton.engine.BaseHandler; |
| import org.apache.qpid.proton.engine.Event; |
| import org.apache.qpid.proton.reactor.Reactor; |
| |
| // Let's try to modify our counter example. In addition to counting to |
| // 10 in quarter second intervals, let's also print out a random number |
| // every half second. This is not a super easy thing to express in a |
| // purely sequential program, but not so difficult using events. |
| public class CountRandomly extends BaseHandler { |
| |
| private long startTime; |
| private CounterHandler counter; |
| |
| class CounterHandler extends BaseHandler { |
| private final int limit; |
| private int count; |
| |
| CounterHandler(int limit) { |
| this.limit = limit; |
| } |
| |
| @Override |
| public void onTimerTask(Event event) { |
| count += 1; |
| System.out.println(count); |
| |
| if (!done()) { |
| event.getReactor().schedule(250, this); |
| } |
| } |
| |
| // Provide a method to check for doneness |
| private boolean done() { |
| return count >= limit; |
| } |
| } |
| |
| @Override |
| public void onReactorInit(Event event) { |
| startTime = System.currentTimeMillis(); |
| System.out.println("Hello, World!"); |
| |
| // Save the counter instance in an attribute so we can refer to |
| // it later. |
| counter = new CounterHandler(10); |
| event.getReactor().schedule(250, counter); |
| |
| // Now schedule another event with a different handler. Note |
| // that the timer tasks go to separate handlers, and they don't |
| // interfere with each other. |
| event.getReactor().schedule(500, this); |
| } |
| |
| @Override |
| public void onTimerTask(Event event) { |
| // keep on shouting until we are done counting |
| System.out.println("Yay, " + Math.round(Math.abs((Math.random() * 110) - 10))); |
| if (!counter.done()) { |
| event.getReactor().schedule(500, this); |
| } |
| } |
| |
| @Override |
| public void onReactorFinal(Event event) { |
| long elapsedTime = System.currentTimeMillis() - startTime; |
| System.out.println("Goodbye, World! (after " + elapsedTime + " long milliseconds)"); |
| } |
| |
| public static void main(String[] args) throws IOException { |
| // In HelloWorld.java we said the reactor exits when there are no more |
| // events to process. While this is true, it's not actually complete. |
| // The reactor exits when there are no more events to process and no |
| // possibility of future events arising. For that reason the reactor |
| // will keep running until there are no more scheduled events and then |
| // exit. |
| Reactor reactor = Proton.reactor(new CountRandomly()); |
| reactor.run(); |
| } |
| } |