001    // Copyright 2010, 2012 The Apache Software Foundation
002    //
003    // Licensed under the Apache License, Version 2.0 (the "License");
004    // you may not use this file except in compliance with the License.
005    // You may obtain a copy of the License at
006    //
007    // http://www.apache.org/licenses/LICENSE-2.0
008    //
009    // Unless required by applicable law or agreed to in writing, software
010    // distributed under the License is distributed on an "AS IS" BASIS,
011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012    // See the License for the specific language governing permissions and
013    // limitations under the License.
014    
015    package org.apache.tapestry5.ioc.internal;
016    
017    import org.apache.tapestry5.ioc.ObjectCreator;
018    import org.apache.tapestry5.ioc.ServiceBuilderResources;
019    import org.apache.tapestry5.ioc.internal.util.InternalUtils;
020    import org.apache.tapestry5.ioc.services.PlasticProxyFactory;
021    
022    import java.lang.reflect.Constructor;
023    
024    /**
025     * Returns an {@link ObjectCreator} for lazily instantiating a given implementation class (with dependencies).
026     * Once an instance is instantiated, it is cached ... until any underlying .class file changes, at which point
027     * the class (and its class dependencies, such as base classes) are reloaded and a new instance instantiated.
028     */
029    @SuppressWarnings("all")
030    public class ReloadableServiceImplementationObjectCreator extends AbstractReloadableObjectCreator
031    {
032        private final ServiceBuilderResources resources;
033    
034        public ReloadableServiceImplementationObjectCreator(PlasticProxyFactory proxyFactory, ServiceBuilderResources resources, ClassLoader baseClassLoader,
035                                                            String implementationClassName)
036        {
037            super(proxyFactory, baseClassLoader, implementationClassName, resources.getLogger(), resources.getTracker());
038    
039            this.resources = resources;
040        }
041    
042        protected Object createInstance(Class clazz)
043        {
044            final Constructor constructor = InternalUtils.findAutobuildConstructor(clazz);
045    
046            if (constructor == null)
047                throw new RuntimeException(String.format(
048                        "Service implementation class %s does not have a suitable public constructor.", clazz.getName()));
049    
050            ObjectCreator constructorServiceCreator = new ConstructorServiceCreator(resources, constructor.toString(),
051                    constructor);
052    
053            return constructorServiceCreator.createObject();
054        }
055    }