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 import org.apache.camel.util.ObjectHelper;
025
026 /**
027 * An implementation of a {@link BeanHolder} which will look up a bean from the registry and act as a cache of its metadata
028 *
029 * @version
030 */
031 public class RegistryBean implements BeanHolder {
032 private final CamelContext context;
033 private final String name;
034 private final Registry registry;
035 private Processor processor;
036 private BeanInfo beanInfo;
037 private 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 return new ConstantBeanHolder(getBean(), getBeanInfo());
059 }
060
061 public synchronized Object getBean() throws NoSuchBeanException {
062 Object value = lookupBean();
063 if (value == null) {
064 // maybe its a class
065 value = context.getClassResolver().resolveClass(name);
066 if (value == null) {
067 // no its not a class then we cannot find the bean
068 throw new NoSuchBeanException(name);
069 }
070 }
071 if (value != bean) {
072 if (!ObjectHelper.equal(ObjectHelper.type(bean), ObjectHelper.type(value))) {
073 beanInfo = null;
074 }
075 bean = value;
076 processor = null;
077
078 // could be a class then create an instance of it
079 if (bean instanceof Class) {
080 // bean is a class so create an instance of it
081 bean = context.getInjector().newInstance((Class<?>)bean);
082 value = bean;
083 }
084 }
085 return value;
086 }
087
088 public Processor getProcessor() {
089 if (processor == null && bean != null) {
090 processor = CamelContextHelper.convertTo(context, Processor.class, bean);
091 }
092 return processor;
093 }
094
095 public BeanInfo getBeanInfo() {
096 if (beanInfo == null && bean != null) {
097 this.beanInfo = createBeanInfo();
098 }
099 return beanInfo;
100 }
101
102 public String getName() {
103 return name;
104 }
105
106 public Registry getRegistry() {
107 return registry;
108 }
109
110 public CamelContext getContext() {
111 return context;
112 }
113
114 public ParameterMappingStrategy getParameterMappingStrategy() {
115 if (parameterMappingStrategy == null) {
116 parameterMappingStrategy = createParameterMappingStrategy();
117 }
118 return parameterMappingStrategy;
119 }
120
121 public void setParameterMappingStrategy(ParameterMappingStrategy parameterMappingStrategy) {
122 this.parameterMappingStrategy = parameterMappingStrategy;
123 }
124
125 // Implementation methods
126 //-------------------------------------------------------------------------
127 protected BeanInfo createBeanInfo() {
128 return new BeanInfo(context, bean.getClass(), getParameterMappingStrategy());
129 }
130
131 protected ParameterMappingStrategy createParameterMappingStrategy() {
132 return BeanInfo.createParameterMappingStrategy(context);
133 }
134
135 protected Object lookupBean() {
136 return registry.lookup(name);
137 }
138 }