AsyncEventBus 示例

package bbejeck.guava.chapter7.async;import bbejeck.guava.chapter7.EventBusTestBase;
import bbejeck.guava.chapter7.subscriber.SlowProcessSubscriber;
import com.google.common.eventbus.AsyncEventBus;
import org.junit.Before;
import org.junit.Test;import java.util.concurrent.CountDownLatch;
import java.util.concurrent.Executors;import static org.junit.Assert.assertTrue;/*** User: Bill Bejeck* Date: 4/29/13* Time: 11:14 PM*/
public class AsyncEventBusTest extends EventBusTestBase {private AsyncEventBus asyncEventBus = new AsyncEventBus(Executors.newCachedThreadPool());private int numberLongEvents = 10;private CountDownLatch doneSignal = new CountDownLatch(numberLongEvents);private SlowProcessSubscriber slowProcessSubscriber;@Beforepublic void setUp() {slowProcessSubscriber = new SlowProcessSubscriber(asyncEventBus, doneSignal);}/*** Handler for BuyEvent has @AllowConcurrentEvents and each invocation* of the handler takes 300 MS, but done in parallel s only takes approximately* 300 MS to run*/@Testpublic void testAsyncEventSubscriber() throws Exception {long start = System.currentTimeMillis();for (int i = 0; i < numberLongEvents; i++) {asyncEventBus.post(buyEventBuilder().build());}doneSignal.await();long elapsed = System.currentTimeMillis() - start;assertTrue(elapsed >= 300l && elapsed < 500l);}/*** Handler for SellEvent does not @AllowConcurrentEvents and each invocation* of the handler takes 300ms, even though using AsyncEventBus it takes a full* 3 seconds to run, so all calls are serial!*/@Testpublic void testNonAsyncEventSubscriber() throws Exception {long start = System.currentTimeMillis();for (int i = 0; i < numberLongEvents; i++) {asyncEventBus.post(sellEventBuilder().build());}doneSignal.await();long elapsed = System.currentTimeMillis() - start;assertTrue(elapsed >= 3000l && elapsed < 5000l);}
}