org.batoo.jpa.core.impl.criteria.join.FetchImpl.java Source code

Introduction

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

Source

/*
 * 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.join;

import java.util.List;

import javax.persistence.criteria.Fetch;
import javax.persistence.criteria.JoinType;

import org.apache.commons.lang.StringUtils;
import org.batoo.jpa.core.impl.criteria.AbstractCriteriaQueryImpl;
import org.batoo.jpa.core.impl.criteria.BaseQueryImpl;
import org.batoo.jpa.core.impl.model.attribute.AttributeImpl;
import org.batoo.jpa.core.impl.model.mapping.JoinedMapping;
import org.batoo.jpa.jdbc.mapping.MappingType;

/**
 * Implementation of {@link Fetch}.
 * 
 * @param <Z>
 *            the source type of the fetch
 * @param <X>
 *            the target type of the fetch
 * 
 * @author hceylan
 * @since 2.0.0
 */
public class FetchImpl<Z, X> extends FetchParentImpl<Z, X> implements Fetch<Z, X> {

    private final FetchParentImpl<?, Z> parent;
    private final JoinedMapping<? super Z, ?, X> mapping;
    private final JoinType joinType;

    /**
     * @param parent
     *            the parent of the join
     * @param mapping
     *            the mapping of the join
     * @param joinType
     *            the join type
     * 
     * @since 2.0.0
     */
    public FetchImpl(FetchParentImpl<?, Z> parent, JoinedMapping<? super Z, ?, X> mapping, JoinType joinType) {
        super(mapping);

        this.parent = parent;
        this.mapping = mapping;
        this.joinType = joinType;
    }

    /**
     * Returns the description of the fetch.
     * 
     * @param parent
     *            the parent
     * @return the description of the fetch
     * 
     * @since 2.0.0
     */
    @Override
    public String generateJpqlFetches(String parent) {
        final StringBuilder builder = new StringBuilder();

        builder.append("left join fetch ");

        builder.append(parent).append(".").append(this.mapping.getAttribute().getName());

        final String children = super.generateJpqlFetches(parent + "." + this.mapping.getAttribute().getName());
        if (StringUtils.isNotBlank(children)) {
            builder.append("\n").append(children);
        }

        return builder.toString();
    }

    /**
     * {@inheritDoc}
     * 
     */
    @Override
    public void generateSqlJoins(AbstractCriteriaQueryImpl<?> query, List<String> selfJoins) {
        final String parentAlias = this.getParent().getPrimaryTableAlias(query);
        final String alias = this.getPrimaryTableAlias(query);

        selfJoins.add(this.mapping.join(parentAlias, alias, this.joinType));

        super.generateSqlJoins(query, selfJoins);
    }

    /**
     * {@inheritDoc}
     * 
     */
    @Override
    public AttributeImpl<? super Z, ?> getAttribute() {
        return this.mapping.getAttribute();
    }

    /**
     * {@inheritDoc}
     * 
     */
    @Override
    public JoinType getJoinType() {
        return this.joinType;
    }

    /**
     * {@inheritDoc}
     * 
     */
    @Override
    public JoinedMapping<? super Z, ?, X> getMapping() {
        return this.mapping;
    }

    /**
     * {@inheritDoc}
     * 
     */
    @Override
    public FetchParentImpl<?, Z> getParent() {
        return this.parent;
    }

    /**
     * {@inheritDoc}
     * 
     */
    @Override
    public String getPrimaryTableAlias(BaseQueryImpl<?> query) {
        if (this.mapping.getMappingType() == MappingType.EMBEDDABLE) {
            return this.parent.getPrimaryTableAlias(query);
        }

        return super.getPrimaryTableAlias(query);
    }
}