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.List;
020 import javax.xml.bind.annotation.XmlAccessType;
021 import javax.xml.bind.annotation.XmlAccessorType;
022 import javax.xml.bind.annotation.XmlTransient;
023 import javax.xml.bind.annotation.XmlType;
024
025 import org.apache.camel.AsyncCallback;
026 import org.apache.camel.Exchange;
027 import org.apache.camel.Processor;
028 import org.apache.camel.processor.loadbalancer.LoadBalancer;
029 import org.apache.camel.spi.RouteContext;
030 import org.apache.camel.util.IntrospectionSupport;
031 import org.apache.camel.util.ObjectHelper;
032
033 /**
034 * Represents an XML <loadBalancer/> element
035 */
036 @XmlType(name = "loadBalancer")
037 @XmlAccessorType(XmlAccessType.FIELD)
038 public class LoadBalancerDefinition extends IdentifiedType implements LoadBalancer {
039 @XmlTransient
040 private LoadBalancer loadBalancer;
041 @XmlTransient
042 private String loadBalancerTypeName;
043
044 public LoadBalancerDefinition() {
045 }
046
047 public LoadBalancerDefinition(LoadBalancer loadBalancer) {
048 this.loadBalancer = loadBalancer;
049 }
050
051 protected LoadBalancerDefinition(String loadBalancerTypeName) {
052 this.loadBalancerTypeName = loadBalancerTypeName;
053 }
054
055 public static LoadBalancer getLoadBalancer(RouteContext routeContext, LoadBalancerDefinition type, String ref) {
056 if (type == null) {
057 ObjectHelper.notNull(ref, "ref or loadBalancer");
058 LoadBalancer loadBalancer = routeContext.mandatoryLookup(ref, LoadBalancer.class);
059 if (loadBalancer instanceof LoadBalancerDefinition) {
060 type = (LoadBalancerDefinition) loadBalancer;
061 } else {
062 return loadBalancer;
063 }
064 }
065 return type.getLoadBalancer(routeContext);
066 }
067
068
069 /**
070 * Sets a named property on the data format instance using introspection
071 */
072 protected void setProperty(Object bean, String name, Object value) {
073 try {
074 IntrospectionSupport.setProperty(bean, name, value);
075 } catch (Exception e) {
076 throw new IllegalArgumentException("Failed to set property " + name + " on " + bean + ". Reason: " + e, e);
077 }
078 }
079
080 /**
081 * Allows derived classes to customize the load balancer
082 */
083 protected void configureLoadBalancer(LoadBalancer loadBalancer) {
084 }
085
086 public LoadBalancer getLoadBalancer(RouteContext routeContext) {
087 if (loadBalancer == null) {
088 loadBalancer = createLoadBalancer(routeContext);
089 ObjectHelper.notNull(loadBalancer, "loadBalancer");
090 configureLoadBalancer(loadBalancer);
091 }
092 return loadBalancer;
093 }
094
095 /**
096 * Factory method to create the load balancer instance
097 */
098 protected LoadBalancer createLoadBalancer(RouteContext routeContext) {
099 if (loadBalancerTypeName != null) {
100 Class<?> type = routeContext.getCamelContext().getClassResolver().resolveClass(loadBalancerTypeName);
101 if (type == null) {
102 throw new IllegalArgumentException("Cannot find class: " + loadBalancerTypeName + " in the classpath");
103 }
104 return (LoadBalancer) ObjectHelper.newInstance(type);
105 }
106 return null;
107 }
108
109
110 public void addProcessor(Processor processor) {
111 ObjectHelper.notNull(loadBalancer, "loadBalancer", this);
112 loadBalancer.addProcessor(processor);
113 }
114
115 public List<Processor> getProcessors() {
116 ObjectHelper.notNull(loadBalancer, "loadBalancer", this);
117 return loadBalancer.getProcessors();
118 }
119
120 public void removeProcessor(Processor processor) {
121 ObjectHelper.notNull(loadBalancer, "loadBalancer", this);
122 loadBalancer.removeProcessor(processor);
123 }
124
125 public void process(Exchange exchange) throws Exception {
126 ObjectHelper.notNull(loadBalancer, "loadBalancer", this);
127 loadBalancer.process(exchange);
128 }
129
130 public boolean process(Exchange exchange, final AsyncCallback callback) {
131 ObjectHelper.notNull(loadBalancer, "loadBalancer");
132 return loadBalancer.process(exchange, new AsyncCallback() {
133 public void done(boolean doneSync) {
134 // only handle the async case
135 if (doneSync) {
136 return;
137 } else {
138 callback.done(false);
139 }
140 }
141 });
142 }
143
144 @Override
145 public String toString() {
146 if (loadBalancer != null) {
147 return loadBalancer.toString();
148 } else {
149 return loadBalancerTypeName;
150 }
151 }
152 }