org.hibernate.criterion.Order.java Source code

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Here is the source code for org.hibernate.criterion.Order.java

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/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
 * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
 */
package org.hibernate.criterion;

import java.io.Serializable;
import java.sql.Types;
import java.util.Locale;

import org.hibernate.Criteria;
import org.hibernate.NullPrecedence;
import org.hibernate.engine.spi.SessionFactoryImplementor;
import org.hibernate.type.Type;

/**
 * Represents an ordering imposed upon the results of a Criteria
 * 
 * @author Gavin King
 * @author Lukasz Antoniak (lukasz dot antoniak at gmail dot com)
 */
public class Order implements Serializable {
    private boolean ascending;
    private boolean ignoreCase;
    private String propertyName;
    private NullPrecedence nullPrecedence;

    /**
     * Ascending order
     *
     * @param propertyName The property to order on
     *
     * @return The build Order instance
     */
    public static Order asc(String propertyName) {
        return new Order(propertyName, true);
    }

    /**
     * Descending order.
     *
     * @param propertyName The property to order on
     *
     * @return The build Order instance
     */
    public static Order desc(String propertyName) {
        return new Order(propertyName, false);
    }

    /**
     * Constructor for Order.  Order instances are generally created by factory methods.
     *
     * @see #asc
     * @see #desc
     */
    protected Order(String propertyName, boolean ascending) {
        this.propertyName = propertyName;
        this.ascending = ascending;
    }

    /**
     * Should this ordering ignore case?  Has no effect on non-character properties.
     *
     * @return {@code this}, for method chaining
     */
    public Order ignoreCase() {
        ignoreCase = true;
        return this;
    }

    /**
     * Defines precedence for nulls.
     *
     * @param nullPrecedence The null precedence to use
     *
     * @return {@code this}, for method chaining
     */
    public Order nulls(NullPrecedence nullPrecedence) {
        this.nullPrecedence = nullPrecedence;
        return this;
    }

    public String getPropertyName() {
        return propertyName;
    }

    @SuppressWarnings("UnusedDeclaration")
    public boolean isAscending() {
        return ascending;
    }

    @SuppressWarnings("UnusedDeclaration")
    public boolean isIgnoreCase() {
        return ignoreCase;
    }

    /**
     * Render the SQL fragment
     *
     * @param criteria The criteria
     * @param criteriaQuery The overall query
     *
     * @return The ORDER BY fragment for this ordering
     */
    public String toSqlString(Criteria criteria, CriteriaQuery criteriaQuery) {
        final String[] columns = criteriaQuery.getColumnsUsingProjection(criteria, propertyName);
        final Type type = criteriaQuery.getTypeUsingProjection(criteria, propertyName);
        final SessionFactoryImplementor factory = criteriaQuery.getFactory();
        final int[] sqlTypes = type.sqlTypes(factory);

        final StringBuilder fragment = new StringBuilder();
        for (int i = 0; i < columns.length; i++) {
            final StringBuilder expression = new StringBuilder();
            boolean lower = false;
            if (ignoreCase) {
                final int sqlType = sqlTypes[i];
                lower = sqlType == Types.VARCHAR || sqlType == Types.CHAR || sqlType == Types.LONGVARCHAR;
            }

            if (lower) {
                expression.append(factory.getDialect().getLowercaseFunction()).append('(');
            }
            expression.append(columns[i]);
            if (lower) {
                expression.append(')');
            }

            fragment.append(factory.getDialect().renderOrderByElement(expression.toString(), null,
                    ascending ? "asc" : "desc",
                    nullPrecedence != null ? nullPrecedence : factory.getSettings().getDefaultNullPrecedence()));
            if (i < columns.length - 1) {
                fragment.append(", ");
            }
        }

        return fragment.toString();
    }

    @Override
    public String toString() {
        return propertyName + ' ' + (ascending ? "asc" : "desc")
                + (nullPrecedence != null ? ' ' + nullPrecedence.name().toLowerCase(Locale.ROOT) : "");
    }
}