lightning-core/src/main/java/org/apache/directmemory/lightning/internal/beans/introspection/AnnotatedTypeIntrospector.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.
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package org.apache.directmemory.lightning.internal.beans.introspection;

import java.lang.annotation.Annotation;
import java.lang.reflect.Field;
import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Set;

import org.apache.directmemory.lightning.Marshaller;
import org.apache.directmemory.lightning.MarshallerContext;
import org.apache.directmemory.lightning.MarshallerStrategy;
import org.apache.directmemory.lightning.TypeBindableMarshaller;
import org.apache.directmemory.lightning.configuration.TypeIntrospector;
import org.apache.directmemory.lightning.generator.PropertyDescriptorFactory;
import org.apache.directmemory.lightning.internal.util.BeanUtil;
import org.apache.directmemory.lightning.internal.util.TypeUtil;
import org.apache.directmemory.lightning.metadata.PropertyDescriptor;

public class AnnotatedTypeIntrospector
    implements TypeIntrospector
{

    private final Class<? extends Annotation> annotationType;

    private final List<String> excludes;

    public AnnotatedTypeIntrospector( Class<? extends Annotation> annotationType, List<String> excludes )
    {
        this.annotationType = annotationType;
        this.excludes = excludes;
    }

    @Override
    public List<PropertyDescriptor> introspect( Type type, MarshallerStrategy marshallerStrategy,
                                                MarshallerContext marshallerContext,
                                                PropertyDescriptorFactory propertyDescriptorFactory )
    {

        if ( !( type instanceof Class ) )
        {
            return Collections.emptyList();
        }

        Class<?> clazz = (Class<?>) type;
        Set<Field> properties = BeanUtil.findPropertiesByClass( clazz, annotationType );

        List<PropertyDescriptor> propertyDescriptors = new ArrayList<PropertyDescriptor>();
        for ( Field property : properties )
        {
            if ( isExcluded( property.getName() ) )
            {
                continue;
            }

            Class<?> fieldType = property.getType();

            Marshaller marshaller = marshallerStrategy.getMarshaller( fieldType, marshallerContext, false );

            if ( marshaller == null && fieldType.isArray() )
            {
                marshaller = marshallerStrategy.getMarshaller( fieldType.getComponentType(), marshallerContext, false );
            }

            if ( marshaller instanceof TypeBindableMarshaller )
            {
                Type[] typeArguments = TypeUtil.getTypeArgument( property.getGenericType() );
                marshaller = ( (TypeBindableMarshaller) marshaller ).bindType( typeArguments );
            }

            propertyDescriptors.add( propertyDescriptorFactory.byField( property, marshaller, clazz ) );
        }

        return propertyDescriptors;
    }

    private boolean isExcluded( String propertyName )
    {
        return excludes.contains( propertyName );
    }

}