    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    }