# OverbookingConcern.java

    /*
     * Copyright 2007, 2008 Niclas Hedhman.
     *
     * 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.tutorials.cargo.step2;

    import org.qi4j.api.concern.ConcernOf;

    public class OverbookingConcern
        extends ConcernOf<ShippingService>
        implements ShippingService
    {
        @Override
        public int makeBooking( Cargo cargo, Voyage voyage )
        {
            double cargoSize = cargo.size().get();
            double aleadyBookedSize = voyage.bookedCargoSize().get();
            double totalCapacity = voyage.capacity().get();

            if( cargoSize + aleadyBookedSize > totalCapacity )
            {
                // Not allowed.
                return -1;
            }
            return next.makeBooking( cargo, voyage );
        }
    }