Java tutorial
/** * 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 camelinaction; import java.util.ArrayList; import java.util.List; import java.util.concurrent.CountDownLatch; import java.util.concurrent.TimeUnit; import org.apache.camel.Exchange; import org.apache.camel.builder.RouteBuilder; import org.apache.camel.impl.SynchronizationAdapter; import org.apache.camel.spi.Synchronization; import org.apache.camel.test.junit4.CamelTestSupport; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.junit.Test; /** * Demonstrating how to use callback to gather a number of concurrent replies within a * given time period. * * @version $Revision: 338 $ */ public class RiderAutoPartsCallbackTest extends CamelTestSupport { private static Log LOG = LogFactory.getLog(RiderAutoPartsCallbackTest.class); private int numPartners = 5; @Test public void testCallback() throws Exception { // related is the list of related items final List<String> relates = new ArrayList<String>(); // latch to count down every time we got a reply final CountDownLatch latch = new CountDownLatch(numPartners); // use this callback to gather the replies and add it to the related list Synchronization callback = new SynchronizationAdapter() { @Override public void onComplete(Exchange exchange) { // get the reply and add it to related String body = exchange.getOut().getBody(String.class); relates.add(body); log.info("Get async reply {}", body); // count down the latch latch.countDown(); } @Override public void onFailure(Exchange exchange) { // count down the latch even if we failed latch.countDown(); } }; // send the same message to the business partners so they can return their feedback String body = "bumper"; for (int i = 0; i < numPartners; i++) { template.asyncCallbackRequestBody("seda:partner:" + i, body, callback); } LOG.info("Send " + numPartners + " messages to partners."); // wait at most 2 seconds or until we got all replies boolean all = latch.await(2000, TimeUnit.MILLISECONDS); // log what we got as reply LOG.info("Got " + relates.size() + " replies, is all? " + all); for (String related : relates) { LOG.info("Related item category is: " + related); } // assert the unit test assertEquals(3, relates.size()); assertEquals("bumper extension", relates.get(0)); assertEquals("bumper filter", relates.get(1)); assertEquals("bumper cover", relates.get(2)); } @Override protected RouteBuilder createRouteBuilder() throws Exception { return new RouteBuilder() { @Override public void configure() throws Exception { // business partner routes with different delays // so some will answer within the period and others wont from("seda:partner:0").delay(500).transform().simple("bumper filter"); from("seda:partner:1").delay(3000).transform().simple("nose panel"); from("seda:partner:2").delay(1000).transform().simple("bumper cover"); from("seda:partner:3").delay(250).transform().simple("bumper extension"); from("seda:partner:4").delay(4000).transform().simple("tow hooks"); } }; } }