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.loadbalancer;
018
019 import java.util.List;
020
021 import javax.xml.bind.annotation.XmlAccessType;
022 import javax.xml.bind.annotation.XmlAccessorType;
023 import javax.xml.bind.annotation.XmlTransient;
024 import javax.xml.bind.annotation.XmlType;
025
026 import org.apache.camel.AsyncCallback;
027 import org.apache.camel.Exchange;
028 import org.apache.camel.Processor;
029 import org.apache.camel.model.IdentifiedType;
030 import org.apache.camel.processor.loadbalancer.LoadBalancer;
031 import org.apache.camel.spi.RouteContext;
032 import org.apache.camel.util.IntrospectionSupport;
033 import org.apache.camel.util.ObjectHelper;
034
035 /**
036 * Represents an XML <loadBalance/> element
037 */
038 @XmlType(name = "loadBalancer")
039 @XmlAccessorType(XmlAccessType.FIELD)
040 public class LoadBalancerDefinition extends IdentifiedType implements LoadBalancer {
041
042 @XmlTransient
043 private LoadBalancer loadBalancer;
044 @XmlTransient
045 private String loadBalancerTypeName;
046
047 public LoadBalancerDefinition() {
048 }
049
050 public LoadBalancerDefinition(LoadBalancer loadBalancer) {
051 this.loadBalancer = loadBalancer;
052 }
053
054 protected LoadBalancerDefinition(String loadBalancerTypeName) {
055 this.loadBalancerTypeName = loadBalancerTypeName;
056 }
057
058 public static LoadBalancer getLoadBalancer(RouteContext routeContext, LoadBalancerDefinition type, String ref) {
059 if (type == null) {
060 ObjectHelper.notNull(ref, "ref or loadBalancer");
061 LoadBalancer loadBalancer = routeContext.lookup(ref, LoadBalancer.class);
062 if (loadBalancer instanceof LoadBalancerDefinition) {
063 type = (LoadBalancerDefinition) loadBalancer;
064 } else {
065 return loadBalancer;
066 }
067 }
068 return type.getLoadBalancer(routeContext);
069 }
070
071
072 /**
073 * Sets a named property on the data format instance using introspection
074 */
075 protected void setProperty(Object bean, String name, Object value) {
076 try {
077 IntrospectionSupport.setProperty(bean, name, value);
078 } catch (Exception e) {
079 throw new IllegalArgumentException("Failed to set property " + name + " on " + bean + ". Reason: " + e, e);
080 }
081 }
082
083 /**
084 * Allows derived classes to customize the load balancer
085 */
086 protected void configureLoadBalancer(LoadBalancer loadBalancer) {
087 }
088
089 public LoadBalancer getLoadBalancer(RouteContext routeContext) {
090 if (loadBalancer == null) {
091 loadBalancer = createLoadBalancer(routeContext);
092 ObjectHelper.notNull(loadBalancer, "loadBalancer");
093 configureLoadBalancer(loadBalancer);
094 }
095 return loadBalancer;
096 }
097
098 /**
099 * Factory method to create the load balancer instance
100 */
101 @SuppressWarnings("unchecked")
102 protected LoadBalancer createLoadBalancer(RouteContext routeContext) {
103 if (loadBalancerTypeName != null) {
104 Class type = routeContext.getCamelContext().getClassResolver().resolveClass(loadBalancerTypeName);
105 if (type == null) {
106 throw new IllegalArgumentException("Cannot find class: " + loadBalancerTypeName + " in the classpath");
107 }
108 return (LoadBalancer) ObjectHelper.newInstance(type);
109 }
110 return null;
111 }
112
113
114 public void addProcessor(Processor processor) {
115 ObjectHelper.notNull(loadBalancer, "loadBalancer", this);
116 loadBalancer.addProcessor(processor);
117 }
118
119 public List<Processor> getProcessors() {
120 ObjectHelper.notNull(loadBalancer, "loadBalancer", this);
121 return loadBalancer.getProcessors();
122 }
123
124 public void removeProcessor(Processor processor) {
125 ObjectHelper.notNull(loadBalancer, "loadBalancer", this);
126 loadBalancer.removeProcessor(processor);
127 }
128
129 public void process(Exchange exchange) throws Exception {
130 ObjectHelper.notNull(loadBalancer, "loadBalancer", this);
131 loadBalancer.process(exchange);
132 }
133
134 public boolean process(Exchange exchange, final AsyncCallback callback) {
135 ObjectHelper.notNull(loadBalancer, "loadBalancer");
136
137 return loadBalancer.process(exchange, new AsyncCallback() {
138 public void done(boolean sync) {
139 // Only handle the async case...
140 if (!sync) {
141 callback.done(sync);
142 }
143 }
144 });
145
146 }
147
148 }