com.impetus.kundera.metadata.processor.relation.OneToManyRelationMetadataProcessor.java Source code

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Here is the source code for com.impetus.kundera.metadata.processor.relation.OneToManyRelationMetadataProcessor.java

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/*******************************************************************************
 * * Copyright 2012 Impetus Infotech.
 *  *
 *  * 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 com.impetus.kundera.metadata.processor.relation;

import java.lang.reflect.Field;
import java.util.Arrays;

import javax.persistence.JoinColumn;
import javax.persistence.OneToMany;

import org.apache.commons.lang.StringUtils;

import com.impetus.kundera.loader.MetamodelLoaderException;
import com.impetus.kundera.metadata.model.EntityMetadata;
import com.impetus.kundera.metadata.model.Relation;
import com.impetus.kundera.metadata.model.attributes.AbstractAttribute;
import com.impetus.kundera.metadata.processor.AbstractEntityFieldProcessor;
import com.impetus.kundera.metadata.validator.EntityValidatorImpl;
import com.impetus.kundera.persistence.EntityManagerFactoryImpl.KunderaMetadata;
import com.impetus.kundera.property.PropertyAccessorHelper;

/**
 * The Class OneToManyRelationMetadataProcessor.
 * 
 * @author Amresh Singh
 */
public class OneToManyRelationMetadataProcessor extends AbstractEntityFieldProcessor
        implements RelationMetadataProcessor {

    /**
     * Instantiates a new one to many relation metadata processor.
     */
    public OneToManyRelationMetadataProcessor(KunderaMetadata kunderaMetadata) {
        super(kunderaMetadata);
        validator = new EntityValidatorImpl();
    }

    @Override
    public void process(Class<?> clazz, EntityMetadata metadata) {
        throw new MetamodelLoaderException("Method call not applicable for Relation processors");
    }

    @Override
    public void addRelationIntoMetadata(Field relationField, EntityMetadata metadata) {

        OneToMany ann = relationField.getAnnotation(OneToMany.class);
        Class<?> targetEntity = PropertyAccessorHelper.getGenericClass(relationField);

        // now, check annotations
        if (null != ann.targetEntity() && !ann.targetEntity().getSimpleName().equals("void")) {
            targetEntity = ann.targetEntity();
        }

        Relation relation = new Relation(relationField, targetEntity, relationField.getType(), ann.fetch(),
                Arrays.asList(ann.cascade()), Boolean.TRUE, ann.mappedBy(), Relation.ForeignKey.ONE_TO_MANY);

        boolean isJoinedByFK = relationField.isAnnotationPresent(JoinColumn.class);

        if (isJoinedByFK) {
            JoinColumn joinColumnAnn = relationField.getAnnotation(JoinColumn.class);
            relation.setJoinColumnName(
                    StringUtils.isBlank(joinColumnAnn.name()) ? relationField.getName() : joinColumnAnn.name());
        }

        else {
            String joinColumnName = ((AbstractAttribute) metadata.getIdAttribute()).getJPAColumnName();
            if (relation.getMappedBy() != null) {
                try {
                    Field mappedField = metadata.getEntityClazz().getDeclaredField(relation.getMappedBy());
                    if (mappedField != null && mappedField.isAnnotationPresent(JoinColumn.class)) {
                        joinColumnName = mappedField.getAnnotation(JoinColumn.class).name();
                    }
                } catch (NoSuchFieldException e) {
                    // do nothing, it means not a case of self association
                } catch (SecurityException e) {
                    // do nothing, it means not a case of self association
                }
            }
            relation.setJoinColumnName(joinColumnName);
        }

        relation.setBiDirectionalField(metadata.getEntityClazz());
        metadata.addRelation(relationField.getName(), relation);
        metadata.setParent(true);
    }

}