001    // Copyright 2006, 2007, 2008, 2009, 2010, 2011 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.services;
016    
017    import org.apache.tapestry5.ioc.ObjectCreator;
018    import org.apache.tapestry5.ioc.ServiceLifecycle;
019    import org.apache.tapestry5.ioc.ServiceResources;
020    import org.apache.tapestry5.ioc.services.Builtin;
021    import org.apache.tapestry5.ioc.services.PerthreadManager;
022    import org.apache.tapestry5.ioc.services.PlasticProxyFactory;
023    
024    /**
025     * Allows a service to exist "per thread" (in each thread). Creates a proxy that delegates to a per-thread instance.
026     * <p/>
027     * This scheme ensures that, although the service builder method will be invoked many times over the life of the
028     * application, the service decoration process occurs only once. The final calling chain is: Service Proxy --&gt;
029     * Interceptor(s) (from Decorators) --&gt; Advise Proxy (from Advisiors) --&gt; PerThread Proxy --&gt; (per thread)
030     * instance.
031     */
032    @SuppressWarnings("all")
033    public class PerThreadServiceLifecycle implements ServiceLifecycle
034    {
035        private final PerthreadManager perthreadManager;
036    
037        private final PlasticProxyFactory proxyFactory;
038    
039        public PerThreadServiceLifecycle(@Builtin
040        PerthreadManager perthreadManager,
041    
042        @Builtin
043        PlasticProxyFactory proxyFactory)
044        {
045            this.perthreadManager = perthreadManager;
046            this.proxyFactory = proxyFactory;
047        }
048    
049        /**
050         * Returns false; this lifecycle represents a service that will be created many times (by each thread).
051         */
052        public boolean isSingleton()
053        {
054            return false;
055        }
056    
057        public Object createService(ServiceResources resources, ObjectCreator creator)
058        {
059            ObjectCreator perThreadCreator = new PerThreadServiceCreator(perthreadManager, creator);
060    
061            Class serviceInterface = resources.getServiceInterface();
062    
063            return proxyFactory.createProxy(serviceInterface, perThreadCreator, String.format("<PerThread Proxy for %s(%s)>", resources.getServiceId(), serviceInterface.getName()));
064        }
065    }