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
015package org.apache.tapestry5.ioc.internal.services;
016
017import org.apache.tapestry5.ioc.ObjectCreator;
018import org.apache.tapestry5.ioc.ServiceLifecycle;
019import org.apache.tapestry5.ioc.ServiceResources;
020import org.apache.tapestry5.ioc.services.Builtin;
021import org.apache.tapestry5.ioc.services.PerthreadManager;
022import 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")
033public 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}