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 org.apache.camel.component.routebox.strategy; import java.net.URI; import java.net.URISyntaxException; import java.util.ArrayList; import java.util.List; import java.util.Map; import java.util.concurrent.Future; import java.util.concurrent.TimeUnit; import org.apache.camel.CamelContext; import org.apache.camel.CamelExchangeException; import org.apache.camel.CamelExecutionException; import org.apache.camel.Endpoint; import org.apache.camel.Exchange; import org.apache.camel.ExchangePattern; import org.apache.camel.Message; import org.apache.camel.Processor; import org.apache.camel.ProducerTemplate; import org.apache.camel.component.routebox.RouteboxEndpoint; import org.apache.camel.impl.SynchronizationAdapter; import org.apache.camel.model.FromDefinition; import org.apache.camel.model.RouteDefinition; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; public class RouteboxDispatcher { private static final transient Log LOG = LogFactory.getLog(RouteboxDispatcher.class); private ProducerTemplate producer; public RouteboxDispatcher(ProducerTemplate producer) { super(); this.producer = producer; } public Exchange dispatchSync(RouteboxEndpoint endpoint, Exchange exchange) throws Exception { URI dispatchUri; Exchange reply; if (LOG.isDebugEnabled()) { LOG.debug("Dispatching exchange " + exchange + " to endpoint " + endpoint.getEndpointUri()); } dispatchUri = selectDispatchUri(endpoint, exchange); if (exchange.getPattern() == ExchangePattern.InOnly) { reply = producer.send(dispatchUri.toASCIIString(), exchange); } else { reply = issueRequest(endpoint, ExchangePattern.InOut, exchange.getIn().getBody(), exchange.getIn().getHeaders()); } return reply; } public Exchange dispatchAsync(RouteboxEndpoint endpoint, Exchange exchange) throws Exception { URI dispatchUri; Exchange reply; if (LOG.isDebugEnabled()) { LOG.debug("Dispatching exchange " + exchange + " to endpoint " + endpoint.getEndpointUri()); } dispatchUri = selectDispatchUri(endpoint, exchange); if (exchange.getPattern() == ExchangePattern.InOnly) { producer.asyncSend(dispatchUri.toASCIIString(), exchange); reply = exchange; } else { Future<Exchange> future = producer.asyncCallback(dispatchUri.toASCIIString(), exchange, new SynchronizationAdapter()); reply = future.get(endpoint.getConfig().getConnectionTimeout(), TimeUnit.MILLISECONDS); } return reply; } protected URI selectDispatchUri(RouteboxEndpoint endpoint, Exchange exchange) throws Exception { URI dispatchUri; List<URI> consumerUris = getInnerContextConsumerList(endpoint.getConfig().getInnerContext()); if (consumerUris.isEmpty()) { throw new CamelExchangeException("No routes found to dispatch in Routebox at " + endpoint, exchange); } else if (consumerUris.size() == 1) { dispatchUri = consumerUris.get(0); } else { if (!endpoint.getConfig().getDispatchMap().isEmpty()) { // apply URI string found in dispatch Map String key = exchange.getIn().getHeader("ROUTE_DISPATCH_KEY", String.class); if (endpoint.getConfig().getDispatchMap().containsKey(key)) { dispatchUri = new URI(endpoint.getConfig().getDispatchMap().get(key)); } else { throw new CamelExchangeException( "No matching entry found in Dispatch Map for ROUTE_DISPATCH_KEY: " + key, exchange); } } else { // apply dispatch strategy dispatchUri = endpoint.getConfig().getDispatchStrategy().selectDestinationUri(consumerUris, exchange); if (dispatchUri == null) { throw new CamelExchangeException("No matching inner routes found for Operation", exchange); } } } if (LOG.isDebugEnabled()) { LOG.debug("Dispatch URI set to: " + dispatchUri.toASCIIString()); } return dispatchUri; } protected List<URI> getInnerContextConsumerList(CamelContext context) throws URISyntaxException { List<URI> consumerList = new ArrayList<URI>(); List<RouteDefinition> routeDefinitions = context.getRouteDefinitions(); for (RouteDefinition routeDefinition : routeDefinitions) { List<FromDefinition> inputs = routeDefinition.getInputs(); for (FromDefinition input : inputs) { consumerList.add(new URI(input.getUri())); } } return consumerList; } public Exchange issueRequest(Endpoint endpoint, ExchangePattern pattern, final Object body, final Map<String, Object> headers) throws CamelExecutionException { Exchange exchange = producer.send(endpoint, pattern, new Processor() { public void process(Exchange exchange) throws Exception { Message in = exchange.getIn(); in.getHeaders().putAll(headers); in.setBody(body); } }); return exchange; } }