001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.camel.reifier;
018
019import org.apache.camel.Channel;
020import org.apache.camel.Processor;
021import org.apache.camel.Route;
022import org.apache.camel.model.LoadBalanceDefinition;
023import org.apache.camel.model.ProcessorDefinition;
024import org.apache.camel.model.loadbalancer.FailoverLoadBalancerDefinition;
025import org.apache.camel.processor.loadbalancer.LoadBalancer;
026import org.apache.camel.reifier.loadbalancer.LoadBalancerReifier;
027
028public class LoadBalanceReifier extends ProcessorReifier<LoadBalanceDefinition> {
029
030    public LoadBalanceReifier(Route route, ProcessorDefinition<?> definition) {
031        super(route, (LoadBalanceDefinition)definition);
032    }
033
034    @Override
035    public Processor createProcessor() throws Exception {
036        LoadBalancer loadBalancer = LoadBalancerReifier.reifier(route, definition.getLoadBalancerType()).createLoadBalancer();
037
038        // some load balancer can only support a fixed number of outputs
039        int max = definition.getLoadBalancerType().getMaximumNumberOfOutputs();
040        int size = definition.getOutputs().size();
041        if (size > max) {
042            throw new IllegalArgumentException("To many outputs configured on " + definition.getLoadBalancerType() + ": " + size + " > " + max);
043        }
044
045        for (ProcessorDefinition<?> processorType : definition.getOutputs()) {
046            // output must not be another load balancer
047            // check for instanceof as the code below as there is
048            // compilation errors on earlier versions of JDK6
049            // on Windows boxes or with IBM JDKs etc.
050            if (LoadBalanceDefinition.class.isInstance(processorType)) {
051                throw new IllegalArgumentException("Loadbalancer already configured to: " + definition.getLoadBalancerType() + ". Cannot set it to: " + processorType);
052            }
053            Processor processor = createProcessor(processorType);
054            Channel channel = wrapChannel(processor, processorType);
055            loadBalancer.addProcessor(channel);
056        }
057
058        Boolean inherit = definition.isInheritErrorHandler();
059        if (definition.getLoadBalancerType() instanceof FailoverLoadBalancerDefinition) {
060            // special for failover load balancer where you can configure it to
061            // not inherit error handler for its children
062            // but the load balancer itself should inherit so Camels error
063            // handler can react afterwards
064            inherit = true;
065        }
066        Processor target = wrapChannel(loadBalancer, definition, inherit);
067        return target;
068    }
069
070}