001    // Copyright 2009 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.util;
016    
017    import java.lang.reflect.Type;
018    
019    /**
020     * Used when invoking a contribute method to guard against a request for the wrong type of configuration interface.
021     */
022    public class WrongConfigurationTypeGuard implements InjectionResources
023    {
024        private final String serviceId;
025    
026        private final Class guardType;
027    
028        private final Class expectedType;
029    
030        public WrongConfigurationTypeGuard(String serviceId, Class guardType, Class expectedType)
031        {
032            this.serviceId = serviceId;
033            this.guardType = guardType;
034            this.expectedType = expectedType;
035        }
036    
037        public <T> T findResource(Class<T> type, Type genericType)
038        {
039            if (type == guardType)
040                throw new IllegalArgumentException(String.format("Service '%s' is configured using %s, not %s.",
041                                                                 serviceId,
042                                                                 expectedType.getName(), guardType.getName()));
043    
044            return null;
045        }
046    }