001    // Copyright 2006, 2008 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.services;
016    
017    import org.apache.tapestry5.ioc.util.StrategyRegistry;
018    
019    import java.util.Map;
020    
021    /**
022     * A service implementation builder that operates around a {@link StrategyRegistry}, implementing a version of the Gang
023     * of Four Strategy pattern.
024     * <p/>
025     * The constructed service is configured with a number of adapters (that implement the same service interface). Method
026     * invocations on the service are routed to one of the adapters.
027     * <p/>
028     * The first parameter of each method is used to select the appropriate adapter.
029     * <p/>
030     * The ideal interface for use with this builder has only one method.
031     */
032    public interface StrategyBuilder
033    {
034        /**
035         * Given a number of adapters implementing the service interface, builds a "dispatcher" implementations that
036         * delegates to the one of the adapters. It is an error if any of the methods takes no parameters.
037         *
038         * @param <S>      the service interface type
039         * @param registry defines the adapters based on parameter type (of the first parameter)
040         * @return a service implementation
041         */
042        <S> S build(StrategyRegistry<S> registry);
043    
044        /**
045         * @param registrations map frm class to the adapter type
046         * @param <S>
047         * @return the dispatcher
048         * @since 5.1.0.0
049         */
050        <S> S build(Class<S> adapterType, Map<Class, S> registrations);
051    }