    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}