cl.troncador.delfin.query.constraint.PrepareOrderAdapter.java Source code

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Here is the source code for cl.troncador.delfin.query.constraint.PrepareOrderAdapter.java

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/*******************************************************************************
 *  Copyright 2016 Benjamin Almarza
 *
 * 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 cl.troncador.delfin.query.constraint;

import java.util.ArrayList;
import java.util.List;

import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.Order;
import javax.persistence.criteria.Path;
import javax.persistence.criteria.Root;
import javax.persistence.metamodel.SingularAttribute;

import org.apache.commons.lang3.tuple.ImmutablePair;
import org.apache.commons.lang3.tuple.Pair;

// TODO: Auto-generated Javadoc
/**
 * The Class PrepareOrderAdapter.
 *
 * @param <T> the generic type
 */
public class PrepareOrderAdapter<T> implements PrepareOrder<T> {

    /**
     * The Enum Direction.
     */
    public enum Direction {
        /** The asc. */
        ASC,
        /** The des. */
        DES
    }

    /** The directioned column list. */
    private List<Pair<SingularAttribute<T, ?>, Direction>> directionedColumnList = new ArrayList<Pair<SingularAttribute<T, ?>, Direction>>();

    /**
     * Instantiates a new prepare order adapter.
     */
    public PrepareOrderAdapter() {
    }

    /**
     * Instantiates a new prepare order adapter.
     *
     * @param column the column
     */
    public PrepareOrderAdapter(SingularAttribute<T, ?> column) {
        add(column);
    }

    /**
     * Instantiates a new prepare order adapter.
     *
     * @param column the column
     * @param order the order
     */
    public PrepareOrderAdapter(SingularAttribute<T, ?> column, Direction order) {
        add(column, order);
    }

    /**
     * Adds the.
     *
     * @param column the column
     * @param direction the direction
     */
    public void add(SingularAttribute<T, ?> column, Direction direction) {
        Pair<SingularAttribute<T, ?>, Direction> pair = new ImmutablePair<SingularAttribute<T, ?>, Direction>(
                column, direction);
        directionedColumnList.add(pair);
    }

    /**
     * Adds the.
     *
     * @param column the column
     */
    public void add(SingularAttribute<T, ?> column) {
        Pair<SingularAttribute<T, ?>, Direction> pair = new ImmutablePair<SingularAttribute<T, ?>, Direction>(
                column, Direction.ASC);
        directionedColumnList.add(pair);
    }

    /* (non-Javadoc)
     * @see cl.troncador.delfin.query.constraint.PrepareOrder#getOrderArray(javax.persistence.criteria.Root, javax.persistence.criteria.CriteriaBuilder)
     */
    public Order[] getOrderArray(Root<T> root, CriteriaBuilder criteriaBuilder) {
        List<Order> orderList = new ArrayList<Order>();

        for (Pair<SingularAttribute<T, ?>, Direction> directionedColumn : directionedColumnList) {
            Direction direction = directionedColumn.getRight();
            SingularAttribute<T, ?> column = directionedColumn.getLeft();
            Path<?> path = root.get(column);
            Order order = null;
            switch (direction) {
            case ASC:
                order = criteriaBuilder.asc(path);
                break;
            case DES:
                order = criteriaBuilder.desc(path);
                break;
            }
            orderList.add(order);
        }
        return orderList.toArray(new Order[orderList.size()]);
    }
}