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