001    // Copyright 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    
016    package org.apache.tapestry5.ioc.internal.util;
017    
018    import org.apache.tapestry5.ioc.Invokable;
019    
020    import java.lang.reflect.InvocationTargetException;
021    import java.lang.reflect.Method;
022    
023    /**
024     * @since 5.3
025     */
026    public class MethodInvoker<T> implements Invokable<T>
027    {
028        private final Object instance;
029    
030        private final Method method;
031    
032        private final Object[] methodParameters;
033    
034        public MethodInvoker(Object instance, Method method, Object[] methodParameters)
035        {
036            this.instance = instance;
037            this.method = method;
038            this.methodParameters = methodParameters;
039        }
040    
041        public T invoke()
042        {
043            Throwable fail;
044    
045            try
046            {
047                Object result = method.invoke(instance, methodParameters);
048    
049                return (T) result;
050            } catch (InvocationTargetException ex)
051            {
052                fail = ex.getTargetException();
053            } catch (Exception ex)
054            {
055                fail = ex;
056            }
057    
058            throw new RuntimeException(String.format("Error invoking method %s: %s",
059                    method, InternalUtils.toMessage(fail)), fail);
060        }
061    }