# ModifiesInjectionProviderFactory.java

    /*
     * Licensed to the Apache Software Foundation (ASF) under one
     * or more contributor license agreements.  See the NOTICE file
     * distributed with this work for additional information
     * regarding copyright ownership.  The ASF licenses this file
     * to you under the Apache License, Version 2.0 (the
     * "License"); you may not use this file except in compliance
     * with the License.  You may obtain a copy of the License at
     *
     *   http://www.apache.org/licenses/LICENSE-2.0
     *
     * Unless required by applicable law or agreed to in writing,
     * software distributed under the License is distributed on an
     * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
     * KIND, either express or implied.  See the License for the
     * specific language governing permissions and limitations
     * under the License.
     */
    package org.qi4j.runtime.injection.provider;

    import org.qi4j.api.composite.CompositeDescriptor;
    import org.qi4j.api.util.Classes;
    import org.qi4j.bootstrap.InvalidInjectionException;
    import org.qi4j.runtime.injection.DependencyModel;
    import org.qi4j.runtime.injection.InjectionContext;
    import org.qi4j.runtime.injection.InjectionProvider;
    import org.qi4j.runtime.injection.InjectionProviderFactory;
    import org.qi4j.runtime.model.Resolution;

    /**
     * JAVADOC
     */
    public final class ModifiesInjectionProviderFactory
        implements InjectionProviderFactory
    {
        @Override
        public InjectionProvider newInjectionProvider( Resolution bindingContext, DependencyModel dependencyModel )
            throws InvalidInjectionException
        {
            if( bindingContext.model() instanceof CompositeDescriptor )
            {
                Class<?> type = Classes.RAW_CLASS.map( dependencyModel.injectionType() );
                if( type.isAssignableFrom( dependencyModel.injectedClass() ) )
                {
                    return new ModifiedInjectionProvider();
                }
                else
                {
                    throw new InvalidInjectionException( "Composite " + bindingContext.model() + " does not implement @ConcernFor type " + type
                        .getName() + " in modifier " + dependencyModel.injectedClass().getName() );
                }
            }
            else
            {
                throw new InvalidInjectionException( "The class " + dependencyModel.injectedClass()
                    .getName() + " is not a modifier" );
            }
        }

        private static class ModifiedInjectionProvider
            implements InjectionProvider
        {
            @Override
            public Object provideInjection( InjectionContext context )
                throws InjectionProviderException
            {
                return context.next();
            }
        }
    }