AssignableConverter.java

/*
 * Copyright 2009 Alin Dreghiciu.
 *
 * 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.ops4j.pax.swissbox.converter.java.lang;

import org.osgi.service.blueprint.container.Converter;
import org.osgi.service.blueprint.container.ReifiedType;
import static org.ops4j.pax.swissbox.converter.internal.Primitives.*;
import static org.ops4j.pax.swissbox.converter.java.lang.FromNullConverter.*;

/**
 * JAVADOC
 *
 * NOTICE: This class contains code originally developed by "Apache Geronimo Project", OSGi Blueprint Implementation.
 *
 * @author <a href="mailto:dev@geronimo.apache.org">Apache Geronimo Project</a>
 * @author Alin Dreghiciu (adreghiciu@gmail.com)
 */
public class AssignableConverter
    implements Converter
{

    public static final AssignableConverter INSTANCE = new AssignableConverter();

    public boolean canConvert( final Object sourceObject,
                               final ReifiedType targetType )
    {
        return FromNullConverter.fromNullConverter().canConvert( sourceObject, targetType )
               || ( targetType.size() == 0
                    && unwrap( targetType.getRawClass() ).isAssignableFrom( unwrap( sourceObject.getClass() ) ) );
    }

    public Object convert( final Object sourceObject,
                           final ReifiedType targetType )
        throws Exception
    {
        if( !canConvert( sourceObject, targetType ) )
        {
            throw new Exception(
                String.format(
                    "%s cannot convert an %s", AssignableConverter.class.getSimpleName(), sourceObject.getClass()
                )
            );
        }

        if( fromNullConverter().canConvert( sourceObject, targetType ) )
        {
            return fromNullConverter().convert( sourceObject, targetType );
        }

        return sourceObject;
    }

    public static AssignableConverter assignableConverter()
    {
        return INSTANCE;
    }

}