001// Copyright 2011-2013 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.util;
016
017import org.apache.tapestry5.commons.ObjectCreator;
018import org.apache.tapestry5.commons.util.ExceptionUtils;
019import org.apache.tapestry5.ioc.Invokable;
020
021import java.lang.reflect.Constructor;
022import java.lang.reflect.InvocationTargetException;
023
024/**
025 * Wraps the invocation of a constructor (with exception reporting) as an {@link Invokable}.
026 *
027 * @since 5.3
028 */
029public class ConstructorInvoker<T> implements Invokable<T>
030{
031    private final Constructor<T> constructor;
032
033    private final ObjectCreator[] constructorParameters;
034
035    public ConstructorInvoker(Constructor constructor, ObjectCreator[] constructorParameters)
036    {
037        this.constructor = constructor;
038        this.constructorParameters = constructorParameters;
039    }
040
041    @Override
042    public T invoke()
043    {
044        Throwable fail;
045
046        Object[] realized = InternalUtils.realizeObjects(constructorParameters);
047
048        try
049        {
050            return constructor.newInstance(realized);
051        } catch (InvocationTargetException ex)
052        {
053            fail = ex.getTargetException();
054        } catch (Exception ex)
055        {
056            fail = ex;
057        }
058
059        throw new RuntimeException(String.format("Error invoking constructor %s: %s",
060                constructor, ExceptionUtils.toMessage(fail)), fail);
061    }
062}