/*******************************************************************************
* Copyright (c) 1998, 2008 Oracle. All rights reserved.
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
* which accompanies this distribution.
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
* and the Eclipse Distribution License is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* Contributors:
* Oracle - initial API and implementation from Oracle TopLink
******************************************************************************/
package org.eclipse.persistence.mappings.converters;
import java.security.AccessController;
import java.security.PrivilegedActionException;
import java.util.EnumSet;
import java.util.Iterator;
import org.eclipse.persistence.sessions.Session;
import org.eclipse.persistence.mappings.DatabaseMapping;
import org.eclipse.persistence.exceptions.ValidationException;
import org.eclipse.persistence.internal.security.PrivilegedAccessHelper;
import org.eclipse.persistence.internal.security.PrivilegedClassForName;
/**
* <b>Purpose</b>: Object type converter is used to match a fixed number of
* database data values to a Java enum object value. It can be used when the
* values on the database and in the Java differ. To create an object type
* converter, simply specify the set of conversion value pairs. A default value
* and one-way conversion are also supported for legacy data situations.
*
* @author Guy Pelletier
* @since Toplink 10.1.4RI
*/
public class EnumTypeConverter extends ObjectTypeConverter {
private Class m_enumClass;
private String m_enumClassName;
/**
* PUBLIC:
* Creating an enum converter this way will create the conversion values
* for you using ordinal or name values.
*/
public EnumTypeConverter(DatabaseMapping mapping, Class enumClass, boolean useOrdinalValues) {
super(mapping);
m_enumClassName = enumClass.getName();
m_enumClass = enumClass;
EnumSet theEnums = EnumSet.allOf(enumClass);
Iterator<Enum> i = theEnums.iterator();
while (i.hasNext()) {
Enum theEnum = i.next();
if (useOrdinalValues) {
addConversionValue(theEnum.ordinal(), theEnum.name());
} else {
addConversionValue(theEnum.name(), theEnum.name());
}
}
}
/**
* PUBLIC:
* Creating an enum converter this way expects that you will provide
* the conversion values separately.
*/
public EnumTypeConverter(DatabaseMapping mapping, String enumClassName) {
super(mapping);
m_enumClassName = enumClassName;
}
/**
* INTERNAL:
* Convert all the class-name-based settings in this converter to actual
* class-based settings. This method is used when converting a project
* that has been built with class names to a project with classes.
* @param classLoader
*/
public void convertClassNamesToClasses(ClassLoader classLoader){
try {
if (PrivilegedAccessHelper.shouldUsePrivilegedAccess()){
try {
m_enumClass = (Class)AccessController.doPrivileged(new PrivilegedClassForName(m_enumClassName, true, classLoader));
} catch (PrivilegedActionException exception) {
throw ValidationException.classNotFoundWhileConvertingClassNames(m_enumClassName, exception.getException());
}
} else {
m_enumClass = org.eclipse.persistence.internal.security.PrivilegedAccessHelper.getClassForName(m_enumClassName, true, classLoader);
}
} catch (ClassNotFoundException exception){
throw ValidationException.classNotFoundWhileConvertingClassNames(m_enumClassName, exception);
}
}
/**
* INTERNAL:
* Returns the corresponding attribute value for the specified field value.
* Wraps the super method to return an Enum type from the string conversion.
*/
public Object convertDataValueToObjectValue(Object fieldValue, Session session) {
Object obj = super.convertDataValueToObjectValue(fieldValue, session);
if (fieldValue == null || obj == null) {
return obj;
} else {
return Enum.valueOf(m_enumClass, (String) obj);
}
}
/**
* INTERNAL:
* Convert Enum object to the data value. Internal enums are stored as
* strings (names) so this method wraps the super method in that if
* breaks down the enum to a string name before converting it.
*/
public Object convertObjectValueToDataValue(Object attributeValue, Session session) {
if (attributeValue == null) {
return super.convertObjectValueToDataValue(null, session);
} else {
return super.convertObjectValueToDataValue(((Enum)attributeValue).name(), session);
}
}
}