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
015package org.apache.tapestry5.ioc.internal;
016
017import org.apache.tapestry5.ioc.ObjectCreator;
018import org.apache.tapestry5.ioc.ServiceBuilderResources;
019import org.apache.tapestry5.ioc.internal.util.InternalUtils;
020import org.apache.tapestry5.ioc.services.PlasticProxyFactory;
021
022import 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")
030public 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    @Override
043    protected Object createInstance(Class clazz)
044    {
045        final Constructor constructor = InternalUtils.findAutobuildConstructor(clazz);
046
047        if (constructor == null)
048            throw new RuntimeException(String.format(
049                    "Service implementation class %s does not have a suitable public constructor.", clazz.getName()));
050
051        ObjectCreator constructorServiceCreator = new ConstructorServiceCreator(resources, constructor.toString(),
052                constructor);
053
054        return constructorServiceCreator.createObject();
055    }
056}