org.batoo.jpa.core.impl.criteria.RootImpl.java Source code

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Here is the source code for org.batoo.jpa.core.impl.criteria.RootImpl.java

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/*
 * Copyright (c) 2012-2013, Batu Alp Ceylan
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
 * Boston, MA  02110-1301  USA
 */

package org.batoo.jpa.core.impl.criteria;

import javax.persistence.criteria.Root;
import javax.persistence.metamodel.EntityType;

import org.apache.commons.lang.StringUtils;
import org.batoo.jpa.core.impl.criteria.join.AbstractFrom;
import org.batoo.jpa.core.impl.model.EntityTypeImpl;
import org.batoo.jpa.core.impl.model.mapping.AbstractMapping;
import org.batoo.jpa.jdbc.EntityTable;

/**
 * A root type in the from clause. Query roots always reference entities.
 * 
 * @param <X>
 *            the entity type referenced by the root
 * @author hceylan
 * @since 2.0.0
 */
public class RootImpl<X> extends AbstractFrom<X, X> implements Root<X> {

    private final EntityTypeImpl<X> entity;

    /**
     * @param entity
     *            the entity
     * 
     * @since 2.0.0
     */
    public RootImpl(EntityTypeImpl<X> entity) {
        super(entity);

        this.entity = entity;
    }

    /**
     * {@inheritDoc}
     * 
     */
    @Override
    public String generateJpqlSelect(AbstractCriteriaQueryImpl<?> query, boolean selected) {
        super.generateJpqlSelect(query, selected);

        if (StringUtils.isNotBlank(this.getAlias())) {
            return this.getAlias();
        }

        return this.getModel().getName();
    }

    /**
     * Returns the generated from SQL fragment.
     * 
     * @param query
     *            the query
     * @return the generated from SQL fragment
     * 
     * @since 2.0.0
     */
    public String generateSqlFrom(BaseQueryImpl<?> query) {
        final EntityTable primaryTable = this.entity.getRootType().getPrimaryTable();

        if (query.isQuery()) {
            return primaryTable.getQName() + " " + this.getFetchRoot().getTableAlias(query, primaryTable);
        }

        return primaryTable.getQName();
    }

    /**
     * {@inheritDoc}
     * 
     */
    @Override
    @SuppressWarnings("unchecked")
    protected <C, Y> AbstractMapping<? super X, C, Y> getMapping(String name) {
        final AbstractMapping<? super X, ?, ?> child = this.entity.getRootMapping().getChild(name);

        if (child == null) {
            throw this.cannotDereference(name);
        }

        return (AbstractMapping<? super X, C, Y>) child;
    }

    /**
     * {@inheritDoc}
     * 
     */
    @Override
    public EntityType<X> getModel() {
        return this.entity;
    }

    /**
     * {@inheritDoc}
     * 
     */
    @Override
    public String toString() {
        return "RootImpl [entity=" + this.entity + "]";
    }
}