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.component.bean;
018
019 import org.apache.camel.CamelContext;
020 import org.apache.camel.NoSuchBeanException;
021 import org.apache.camel.Processor;
022 import org.apache.camel.spi.Registry;
023 import org.apache.camel.util.CamelContextHelper;
024
025 /**
026 * An implementation of a {@link BeanHolder} which will look up a bean from the registry and act as a cache of its metadata
027 *
028 * @version
029 */
030 public class RegistryBean implements BeanHolder {
031 private final Object lock = new Object();
032 private final CamelContext context;
033 private final String name;
034 private final Registry registry;
035 private volatile Processor processor;
036 private volatile BeanInfo beanInfo;
037 private volatile Object bean;
038 private ParameterMappingStrategy parameterMappingStrategy;
039
040 public RegistryBean(CamelContext context, String name) {
041 this.context = context;
042 this.name = name;
043 this.registry = context.getRegistry();
044 }
045
046 public RegistryBean(Registry registry, CamelContext context, String name) {
047 this.registry = registry;
048 this.context = context;
049 this.name = name;
050 }
051
052 @Override
053 public String toString() {
054 return "bean: " + name;
055 }
056
057 public ConstantBeanHolder createCacheHolder() throws Exception {
058 Object bean = getBean();
059 BeanInfo info = createBeanInfo(bean);
060 return new ConstantBeanHolder(bean, info);
061 }
062
063 public Object getBean() throws NoSuchBeanException {
064 // must always lookup bean first
065 Object value = lookupBean();
066
067 if (value != null) {
068 // could be a class then create an instance of it
069 if (value instanceof Class) {
070 // bean is a class so create an instance of it
071 value = context.getInjector().newInstance((Class<?>)value);
072 }
073 bean = value;
074 return value;
075 }
076
077 // okay bean is not in registry, so try to resolve if its a class name and create a shared instance
078 synchronized (lock) {
079 if (bean != null) {
080 return bean;
081 }
082
083 // maybe its a class
084 bean = context.getClassResolver().resolveClass(name);
085 if (bean == null) {
086 // no its not a class then we cannot find the bean
087 throw new NoSuchBeanException(name);
088 }
089 // could be a class then create an instance of it
090 if (bean instanceof Class) {
091 // bean is a class so create an instance of it
092 bean = context.getInjector().newInstance((Class<?>)bean);
093 }
094 }
095
096 return bean;
097 }
098
099 public Processor getProcessor() {
100 if (processor == null && bean != null) {
101 processor = CamelContextHelper.convertTo(context, Processor.class, bean);
102 }
103 return processor;
104 }
105
106 public BeanInfo getBeanInfo() {
107 if (beanInfo == null && bean != null) {
108 this.beanInfo = createBeanInfo(bean);
109 }
110 return beanInfo;
111 }
112
113 public BeanInfo getBeanInfo(Object bean) {
114 if (this.bean == bean) {
115 return getBeanInfo();
116 } else {
117 return createBeanInfo(bean);
118 }
119 }
120
121 public String getName() {
122 return name;
123 }
124
125 public Registry getRegistry() {
126 return registry;
127 }
128
129 public CamelContext getContext() {
130 return context;
131 }
132
133 public ParameterMappingStrategy getParameterMappingStrategy() {
134 if (parameterMappingStrategy == null) {
135 parameterMappingStrategy = createParameterMappingStrategy();
136 }
137 return parameterMappingStrategy;
138 }
139
140 public void setParameterMappingStrategy(ParameterMappingStrategy parameterMappingStrategy) {
141 this.parameterMappingStrategy = parameterMappingStrategy;
142 }
143
144 // Implementation methods
145 //-------------------------------------------------------------------------
146 protected BeanInfo createBeanInfo(Object bean) {
147 return new BeanInfo(context, bean.getClass(), getParameterMappingStrategy());
148 }
149
150 protected ParameterMappingStrategy createParameterMappingStrategy() {
151 return BeanInfo.createParameterMappingStrategy(context);
152 }
153
154 protected Object lookupBean() {
155 return registry.lookupByName(name);
156 }
157 }