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.AsyncProcessorHelper;
031 import org.apache.camel.util.IntrospectionSupport;
032 import org.apache.camel.util.ObjectHelper;
033
034 /**
035 * Represents an XML <loadBalancer/> element
036 */
037 @XmlType(name = "loadBalancer")
038 @XmlAccessorType(XmlAccessType.FIELD)
039 public class LoadBalancerDefinition extends IdentifiedType implements LoadBalancer {
040 @XmlTransient
041 private LoadBalancer loadBalancer;
042 @XmlTransient
043 private String loadBalancerTypeName;
044
045 public LoadBalancerDefinition() {
046 }
047
048 public LoadBalancerDefinition(LoadBalancer loadBalancer) {
049 this.loadBalancer = loadBalancer;
050 }
051
052 protected LoadBalancerDefinition(String loadBalancerTypeName) {
053 this.loadBalancerTypeName = loadBalancerTypeName;
054 }
055
056 public static LoadBalancer getLoadBalancer(RouteContext routeContext, LoadBalancerDefinition type, String ref) {
057 if (type == null) {
058 ObjectHelper.notNull(ref, "ref or loadBalancer");
059 LoadBalancer loadBalancer = routeContext.lookup(ref, LoadBalancer.class);
060 if (loadBalancer instanceof LoadBalancerDefinition) {
061 type = (LoadBalancerDefinition) loadBalancer;
062 } else {
063 return loadBalancer;
064 }
065 }
066 return type.getLoadBalancer(routeContext);
067 }
068
069
070 /**
071 * Sets a named property on the data format instance using introspection
072 */
073 protected void setProperty(Object bean, String name, Object value) {
074 try {
075 IntrospectionSupport.setProperty(bean, name, value);
076 } catch (Exception e) {
077 throw new IllegalArgumentException("Failed to set property " + name + " on " + bean + ". Reason: " + e, e);
078 }
079 }
080
081 /**
082 * Allows derived classes to customize the load balancer
083 */
084 protected void configureLoadBalancer(LoadBalancer loadBalancer) {
085 }
086
087 public LoadBalancer getLoadBalancer(RouteContext routeContext) {
088 if (loadBalancer == null) {
089 loadBalancer = createLoadBalancer(routeContext);
090 ObjectHelper.notNull(loadBalancer, "loadBalancer");
091 configureLoadBalancer(loadBalancer);
092 }
093 return loadBalancer;
094 }
095
096 /**
097 * Factory method to create the load balancer instance
098 */
099 protected LoadBalancer createLoadBalancer(RouteContext routeContext) {
100 if (loadBalancerTypeName != null) {
101 Class<?> type = routeContext.getCamelContext().getClassResolver().resolveClass(loadBalancerTypeName);
102 if (type == null) {
103 throw new IllegalArgumentException("Cannot find class: " + loadBalancerTypeName + " in the classpath");
104 }
105 return (LoadBalancer) ObjectHelper.newInstance(type);
106 }
107 return null;
108 }
109
110
111 public void addProcessor(Processor processor) {
112 ObjectHelper.notNull(loadBalancer, "loadBalancer", this);
113 loadBalancer.addProcessor(processor);
114 }
115
116 public List<Processor> getProcessors() {
117 ObjectHelper.notNull(loadBalancer, "loadBalancer", this);
118 return loadBalancer.getProcessors();
119 }
120
121 public void removeProcessor(Processor processor) {
122 ObjectHelper.notNull(loadBalancer, "loadBalancer", this);
123 loadBalancer.removeProcessor(processor);
124 }
125
126 public void process(Exchange exchange) throws Exception {
127 ObjectHelper.notNull(loadBalancer, "loadBalancer", this);
128 loadBalancer.process(exchange);
129 }
130
131 public boolean process(Exchange exchange, final AsyncCallback callback) {
132 ObjectHelper.notNull(loadBalancer, "loadBalancer");
133 return AsyncProcessorHelper.process(loadBalancer, exchange, new AsyncCallback() {
134 public void done(boolean doneSync) {
135 // only handle the async case
136 if (doneSync) {
137 return;
138 } else {
139 callback.done(false);
140 }
141 }
142 });
143 }
144
145 @Override
146 public String toString() {
147 if (loadBalancer != null) {
148 return loadBalancer.toString();
149 } else {
150 return loadBalancerTypeName;
151 }
152 }
153 }