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
015package org.apache.tapestry5.ioc.internal.util;
016
017import org.apache.tapestry5.ioc.Invokable;
018import org.apache.tapestry5.ioc.ObjectCreator;
019
020import java.lang.reflect.Constructor;
021import java.lang.reflect.InvocationTargetException;
022
023/**
024 * Wraps the invocation of a constructor (with exception reporting) as an {@link Invokable}.
025 *
026 * @since 5.3
027 */
028public class ConstructorInvoker<T> implements Invokable<T>
029{
030    private final Constructor<T> constructor;
031
032    private final ObjectCreator[] constructorParameters;
033
034    public ConstructorInvoker(Constructor constructor, ObjectCreator[] constructorParameters)
035    {
036        this.constructor = constructor;
037        this.constructorParameters = constructorParameters;
038    }
039
040    public T invoke()
041    {
042        Throwable fail;
043
044        Object[] realized = InternalUtils.realizeObjects(constructorParameters);
045
046        try
047        {
048            return constructor.newInstance(realized);
049        } catch (InvocationTargetException ex)
050        {
051            fail = ex.getTargetException();
052        } catch (Exception ex)
053        {
054            fail = ex;
055        }
056
057        throw new RuntimeException(String.format("Error invoking constructor %s: %s",
058                constructor, InternalUtils.toMessage(fail)), fail);
059    }
060}