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.geronimo.gbean.runtime;
018    
019    import org.apache.geronimo.gbean.AbstractName;
020    import org.apache.geronimo.gbean.GReferenceInfo;
021    import org.apache.geronimo.gbean.InvalidConfigurationException;
022    import org.apache.geronimo.kernel.ClassLoading;
023    import org.apache.geronimo.kernel.GBeanNotFoundException;
024    import org.apache.geronimo.kernel.Kernel;
025    import org.apache.geronimo.kernel.management.State;
026    import org.apache.commons.logging.Log;
027    import org.apache.commons.logging.LogFactory;
028    
029    import java.lang.reflect.Method;
030    import java.lang.reflect.Modifier;
031    
032    /**
033     * @version $Rev: 706640 $ $Date: 2008-10-21 14:44:05 +0000 (Tue, 21 Oct 2008) $
034     */
035    public abstract class AbstractGBeanReference implements GBeanReference {
036        /**
037         * Should we proxy references.
038         */
039        protected static final boolean NO_PROXY;
040        static {
041            Log log = LogFactory.getLog(AbstractGBeanReference.class);
042            String no_proxy = System.getProperty("Xorg.apache.geronimo.gbean.NoProxy", "true");
043            NO_PROXY = no_proxy.equalsIgnoreCase("true");
044            if (NO_PROXY) {
045                log.info("GBean references are not using proxies");
046            } else {
047                log.info("GBean references are using proxies");
048            }
049        }
050    
051        /**
052         * Name of this reference.
053         */
054        private final String name;
055    
056        /**
057         * Interface this GBeanInstance uses to refer to the other.
058         */
059        private final Class referenceType;
060    
061        /**
062         * Proxy type which is injected into the GBeanInstance.
063         */
064        private final Class proxyType;
065    
066        /**
067         * The GBeanInstance to which this reference belongs.
068         */
069        private final GBeanInstance gbeanInstance;
070    
071        /**
072         * The method that will be called to set the attribute value.  If null, the value will be set with
073         * a constructor argument
074         */
075        private final MethodInvoker setInvoker;
076    
077        private final boolean hasTargets;
078    
079        /**
080         * The metadata for this reference
081         */
082        private final GReferenceInfo referenceInfo;
083    
084        /**
085         * The kernel to which the reference is bound.
086         */
087        private final Kernel kernel;
088    
089        /**
090         * Proxy for this reference
091         */
092        private Object proxy;
093    
094    
095        public AbstractGBeanReference(GBeanInstance gbeanInstance, GReferenceInfo referenceInfo, Kernel kernel, boolean hasTargets) throws InvalidConfigurationException {
096            this.gbeanInstance = gbeanInstance;
097            this.referenceInfo = referenceInfo;
098            this.kernel = kernel;
099            this.hasTargets = hasTargets;
100    
101            this.name = referenceInfo.getName();
102            try {
103                this.referenceType = ClassLoading.loadClass(referenceInfo.getReferenceType(), gbeanInstance.getType().getClassLoader());
104            } catch (ClassNotFoundException e) {
105                throw new InvalidConfigurationException("Could not load Reference Type: " + getDescription(), e);
106            }
107            if (Modifier.isFinal(referenceType.getModifiers())) {
108                throw new IllegalArgumentException("Proxy interface cannot be a final class: " + referenceType.getName());
109            }
110            try {
111                this.proxyType = ClassLoading.loadClass(referenceInfo.getProxyType(), gbeanInstance.getType().getClassLoader());
112            } catch (ClassNotFoundException e) {
113                throw new InvalidConfigurationException("Could not load Proxy Type:" + getDescription(), e);
114            }
115    
116            if (referenceInfo.getSetterName() != null) {
117                try {
118                    String setterName = referenceInfo.getSetterName();
119                    Method setterMethod = gbeanInstance.getType().getMethod(setterName, new Class[] {proxyType});
120                    if (NO_PROXY) {
121                        setInvoker = new ReflectionMethodInvoker(setterMethod);
122                    } else {
123                        setInvoker = new FastMethodInvoker(setterMethod);
124                    }
125                } catch (NoSuchMethodException e) {
126                    throw new InvalidConfigurationException("Setter method not found " + getDescription(), e);
127                }
128            } else {
129                setInvoker = null;
130            }
131    
132        }
133    
134        protected final Kernel getKernel() {
135            return kernel;
136        }
137    
138        public final GBeanInstance getGBeanInstance() {
139            return gbeanInstance;
140        }
141    
142        public final String getName() {
143            return name;
144        }
145    
146        public final GReferenceInfo getReferenceInfo() {
147            return referenceInfo;
148        }
149    
150        public final Class getReferenceType() {
151            return referenceType;
152        }
153    
154        public final Class getProxyType() {
155            return proxyType;
156        }
157    
158        public final Object getProxy() {
159            return proxy;
160        }
161    
162        protected final void setProxy(Object proxy) {
163            this.proxy = proxy;
164        }
165    
166        /**
167         * Is the component in the Running state
168         *
169         * @param abstractName name of the component to check
170         * @return true if the component is running; false otherwise
171         */
172        protected boolean isRunning(Kernel kernel, AbstractName abstractName) {
173            try {
174                final int state = kernel.getGBeanState(abstractName);
175                return state == State.RUNNING_INDEX;
176            } catch (GBeanNotFoundException e) {
177                // mbean is no longer registerd
178                return false;
179            } catch (Exception e) {
180                // problem getting the attribute, mbean has most likely failed
181                return false;
182            }
183        }
184    
185        protected final String getDescription() {
186            return "\n    GBeanInstance: " + gbeanInstance.getName() +
187                    "\n    Reference Name: " + getName() +
188                    "\n    Reference Type: " + referenceInfo.getReferenceType() +
189                    "\n    Proxy Type: " + referenceInfo.getProxyType();
190        }
191    
192        public final synchronized void inject(Object target) throws Exception {
193            // set the proxy into the instance
194            if (setInvoker != null && hasTargets) {
195                setInvoker.invoke(target, new Object[]{getProxy()});
196            }
197        }
198    }