# ServiceFactoryBean.java

    /*  Copyright 2008 Edward Yakop.
    *
    * Licensed 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.library.spring.bootstrap.internal.service;

    import org.qi4j.api.service.ServiceReference;
    import org.qi4j.api.structure.Application;
    import org.springframework.beans.factory.FactoryBean;

    import static org.qi4j.functional.Iterables.first;
    import static org.springframework.util.Assert.notNull;

    public final class ServiceFactoryBean
        implements FactoryBean
    {
        private ServiceReference serviceReference;

        public ServiceFactoryBean( Application anApplication, String aServiceId )
            throws IllegalArgumentException
        {
            notNull( anApplication, "Argument [anApplication] must not be [null]." );
            notNull( aServiceId, "Argument [aServiceId] must not be [null]." );

            ServiceLocator serviceLocator = new ServiceLocator( aServiceId );
            anApplication.descriptor().accept( serviceLocator );
            serviceReference = serviceLocator.locateService( anApplication );

            if( serviceReference == null )
            {
                throw new IllegalArgumentException( "Zest service with id [" + aServiceId + "] is not found." );
            }
        }

        @Override
        public final Object getObject()
            throws Exception
        {
            return serviceReference.get();
        }

        @Override
        public final Class getObjectType()
        {
            return first( serviceReference.types() );
        }

        @Override
        public final boolean isSingleton()
        {
            return false;
        }
    }