org.hibernate.NullPrecedence 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
* Boston, MA 02110-1301 USA
*/
package org.hibernate;
/**
* Defines precedence of null values within {@code ORDER BY} clause.
*
* @author Lukasz Antoniak (lukasz dot antoniak at gmail dot com)
*/
public enum NullPrecedence {
/**
* Null precedence not specified. Relies on the RDBMS implementation.
*/
NONE,
/**
* Null values appear at the beginning of the sorted collection.
*/
FIRST,
/**
* Null values appear at the end of the sorted collection.
*/
LAST;
/**
* Interprets a string representation of a NullPrecedence, returning {@code null} by default. For
* alternative default handling, see {@link #parse(String, NullPrecedence)}
*
* @param name The String representation to interpret
*
* @return The recognized NullPrecedence, or {@code null}
*/
public static NullPrecedence parse(String name) {
if ( "none".equalsIgnoreCase( name ) ) {
return NullPrecedence.NONE;
}
else if ( "first".equalsIgnoreCase( name ) ) {
return NullPrecedence.FIRST;
}
else if ( "last".equalsIgnoreCase( name ) ) {
return NullPrecedence.LAST;
}
return null;
}
/**
* Interprets a string representation of a NullPrecedence, returning the specified default if not recognized.
*
* @param name The String representation to interpret
* @param defaultValue The default value to use
*
* @return The recognized NullPrecedence, or {@code defaultValue}.
*/
public static NullPrecedence parse(String name, NullPrecedence defaultValue) {
final NullPrecedence value = parse( name );
return value != null ? value : defaultValue;
}
}