org.hibernate.dialect.pagination.LimitHelper Maven / Gradle / Ivy
/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2013, Red Hat Inc. or third-party contributors as
* indicated by the @author tags or express copyright attribution
* statements applied by the authors. All third-party contributions are
* distributed under license by Red Hat Inc.
*
* 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
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*/
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() {
}
}