org.hibernate.dialect.pagination.LimitHelper.java Source code

Introduction

Here is the source code for org.hibernate.dialect.pagination.LimitHelper.java

Source

/*
 * 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.dialect.pagination;

import org.hibernate.engine.spi.RowSelection;

/**
 * A helper for dealing with LimitHandler implementations
 *
 * @author Lukasz Antoniak (lukasz dot antoniak at gmail dot com)
 */
public class LimitHelper {
    /**
     * Is a max row limit indicated?
     *
     * @param selection The row selection options
     *
     * @return Whether a max row limit was indicated
     */
    public static boolean hasMaxRows(RowSelection selection) {
        return selection != null && selection.getMaxRows() != null && selection.getMaxRows() > 0;
    }

    /**
     * Should limit be applied?
     *
     * @param limitHandler The limit handler
     * @param selection The row selection
     *
     * @return Whether limiting is indicated
     */
    public static boolean useLimit(LimitHandler limitHandler, RowSelection selection) {
        return limitHandler.supportsLimit() && hasMaxRows(selection);
    }

    /**
     * Is a first row limit indicated?
     *
     * @param selection The row selection options
     *
     * @return Whether a first row limit in indicated
     */
    public static boolean hasFirstRow(RowSelection selection) {
        return getFirstRow(selection) > 0;
    }

    /**
     * Retrieve the indicated first row for pagination
     *
     * @param selection The row selection options
     *
     * @return The first row
     */
    public static int getFirstRow(RowSelection selection) {
        return (selection == null || selection.getFirstRow() == null) ? 0 : selection.getFirstRow();
    }

    private LimitHelper() {
    }
}