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     */
017    package org.apache.camel.model;
018    
019    import java.util.Collection;
020    import java.util.List;
021    
022    import javax.xml.bind.annotation.XmlAccessType;
023    import javax.xml.bind.annotation.XmlAccessorType;
024    import javax.xml.bind.annotation.XmlAttribute;
025    import javax.xml.bind.annotation.XmlElement;
026    import javax.xml.bind.annotation.XmlElements;
027    import javax.xml.bind.annotation.XmlRootElement;
028    
029    import org.apache.camel.Exchange;
030    import org.apache.camel.Expression;
031    import org.apache.camel.Processor;
032    import org.apache.camel.model.loadbalancer.LoadBalancerType;
033    import org.apache.camel.model.loadbalancer.RandomLoadBalanceStrategy;
034    import org.apache.camel.model.loadbalancer.RoundRobinLoadBalanceStrategy;
035    import org.apache.camel.model.loadbalancer.StickyLoadBalanceStrategy;
036    import org.apache.camel.model.loadbalancer.TopicLoadBalanceStrategy;
037    import org.apache.camel.processor.SendProcessor;
038    import org.apache.camel.processor.loadbalancer.LoadBalancer;
039    import org.apache.camel.processor.loadbalancer.RandomLoadBalancer;
040    import org.apache.camel.processor.loadbalancer.RoundRobinLoadBalancer;
041    import org.apache.camel.processor.loadbalancer.StickyLoadBalancer;
042    import org.apache.camel.processor.loadbalancer.TopicLoadBalancer;
043    import org.apache.camel.spi.RouteContext;
044    import org.apache.camel.util.CollectionStringBuffer;
045    
046    /**
047     * Represents an XML <loadBalance/> element
048     */
049    @XmlRootElement(name = "loadBalance")
050    @XmlAccessorType(XmlAccessType.FIELD)
051    public class LoadBalanceType extends OutputType<LoadBalanceType> {
052        @XmlAttribute(required = false)
053        private String ref;
054    
055        @XmlElements({
056            @XmlElement(required = false, name = "roundRobin", type = RoundRobinLoadBalanceStrategy.class),
057            @XmlElement(required = false, name = "random", type = RandomLoadBalanceStrategy.class),
058            @XmlElement(required = false, name = "sticky", type = StickyLoadBalanceStrategy.class),
059            @XmlElement(required = false, name = "topic", type = TopicLoadBalanceStrategy.class)}
060            )
061        private LoadBalancerType loadBalancerType;
062    
063        public LoadBalanceType() {
064        }
065    
066        public String getRef() {
067            return ref;
068        }
069    
070        public void setRef(String ref) {
071            this.ref = ref;
072        }
073    
074        public LoadBalancerType getLoadBalancerType() {
075            return loadBalancerType;
076        }
077    
078        public void setLoadBalancerType(LoadBalancerType loadbalancer) {
079            loadBalancerType = loadbalancer;
080        }
081    
082        protected Processor createOutputsProcessor(RouteContext routeContext, Collection<ProcessorType<?>> outputs)
083            throws Exception {
084            LoadBalancer loadBalancer = LoadBalancerType.getLoadBalancer(routeContext, loadBalancerType, ref);
085            for (ProcessorType processorType : outputs) {
086                // The outputs should be the SendProcessor
087                SendProcessor processor = (SendProcessor) processorType.createProcessor(routeContext);
088                loadBalancer.addProcessor(processor);
089            }
090            return loadBalancer;
091        }
092    
093        // when this method will be called
094        @Override
095        public Processor createProcessor(RouteContext routeContext) throws Exception {
096            LoadBalancer loadBalancer = LoadBalancerType.getLoadBalancer(routeContext, loadBalancerType, ref);
097            for (ProcessorType processorType : getOutputs()) {
098                // The outputs should be the SendProcessor
099                SendProcessor processor = (SendProcessor) processorType.createProcessor(routeContext);
100                loadBalancer.addProcessor(processor);
101            }
102    
103            return loadBalancer;
104        }
105    
106        // Fluent API
107        // -------------------------------------------------------------------------
108        public LoadBalanceType setLoadBalancer(LoadBalancer loadBalancer) {
109            loadBalancerType = new LoadBalancerType(loadBalancer);
110            return this;
111        }
112    
113        public LoadBalanceType roundRobin() {
114            loadBalancerType = new LoadBalancerType(new RoundRobinLoadBalancer());
115            return this;
116        }
117    
118        public LoadBalanceType random() {
119            loadBalancerType = new LoadBalancerType(new RandomLoadBalancer());
120            return this;
121        }
122    
123        public LoadBalanceType sticky(Expression<Exchange> correlationExpression) {
124            loadBalancerType = new LoadBalancerType(new StickyLoadBalancer(correlationExpression));
125            return this;
126        }
127    
128        public LoadBalanceType topic() {
129            loadBalancerType = new LoadBalancerType(new TopicLoadBalancer());
130            return this;
131        }
132    
133        @Override
134        public String getLabel() {
135            CollectionStringBuffer buffer = new CollectionStringBuffer();
136            List<ProcessorType<?>> list = getOutputs();
137            for (ProcessorType<?> processorType : list) {
138                buffer.append(processorType.getLabel());
139            }
140            return buffer.toString();
141        }
142    
143        @Override
144        public String toString() {
145            String result;
146            if (loadBalancerType != null) {
147                result = "LoadBalanceType[" + loadBalancerType + ", ";
148            } else {
149                result =  "LoadBalanceType[" + ref + ", ";
150            }
151            result = result + getOutputs() + "]";
152            return result;
153        }
154    
155    }