    001    // Copyright 2010, 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    package org.apache.tapestry5.ioc.internal;
    016
    017    import org.apache.tapestry5.ioc.ObjectLocator;
    018    import org.apache.tapestry5.ioc.internal.util.InternalUtils;
    019
    020    public abstract class AbstractConfigurationImpl<T>
    021    {
    022        private final Class<T> contributionType;
    023
    024        private final ObjectLocator locator;
    025
    026        public AbstractConfigurationImpl(Class<T> contributionType, ObjectLocator locator)
    027        {
    028            this.contributionType = contributionType;
    029            this.locator = locator;
    030        }
    031
    032        protected T instantiate(Class<? extends T> clazz)
    033        {
    034            assert clazz != null;
    035
    036            // Only attempt to proxy the class if it is the right type for the contribution. Starting
    037            // in 5.3, it is allowed to make contributions of different types (as long as they can be
    038            // coerced to the right type) ... but this means that sometimes, a class is passed that isn't
    039            // assignable to the actual contribution type.
    040
    041            if (contributionType.isInterface() && InternalUtils.isLocalFile(clazz)
    042                    && contributionType.isAssignableFrom(clazz))
    043                return locator.proxy(contributionType, clazz);
    044
    045            return locator.autobuild(clazz);
    046        }
    047    }