//$Id: UnsavedValueFactory.java 7736 2005-08-03 20:03:34Z steveebersole $
package org.hibernate.engine;
import java.io.Serializable;
import java.lang.reflect.Constructor;
import org.hibernate.InstantiationException;
import org.hibernate.MappingException;
import org.hibernate.property.Getter;
import org.hibernate.type.IdentifierType;
import org.hibernate.type.PrimitiveType;
import org.hibernate.type.Type;
import org.hibernate.type.VersionType;
/**
* @author Gavin King
*/
public class UnsavedValueFactory {
private static Object instantiate(Constructor constructor) {
try {
return constructor.newInstance(null);
}
catch (Exception e) {
throw new InstantiationException( "could not instantiate test object", constructor.getDeclaringClass(), e );
}
}
/**
* Return an IdentifierValue for the specified unsaved-value. If none is specified,
* guess the unsaved value by instantiating a test instance of the class and
* reading it's id property, or if that is not possible, using the java default
* value for the type
*/
public static IdentifierValue getUnsavedIdentifierValue(
String unsavedValue,
Getter identifierGetter,
Type identifierType,
Constructor constructor) {
if ( unsavedValue == null ) {
if ( identifierGetter!=null && constructor!=null ) {
// use the id value of a newly instantiated instance as the unsaved-value
Serializable defaultValue = (Serializable) identifierGetter.get( instantiate(constructor) );
return new IdentifierValue( defaultValue );
}
else if ( identifierGetter != null && (identifierType instanceof PrimitiveType) ) {
Serializable defaultValue = ( ( PrimitiveType ) identifierType ).getDefaultValue();
return new IdentifierValue( defaultValue );
}
else {
return IdentifierValue.NULL;
}
}
else if ( "null".equals( unsavedValue ) ) {
return IdentifierValue.NULL;
}
else if ( "undefined".equals( unsavedValue ) ) {
return IdentifierValue.UNDEFINED;
}
else if ( "none".equals( unsavedValue ) ) {
return IdentifierValue.NONE;
}
else if ( "any".equals( unsavedValue ) ) {
return IdentifierValue.ANY;
}
else {
try {
return new IdentifierValue( ( Serializable ) ( ( IdentifierType ) identifierType ).stringToObject( unsavedValue ) );
}
catch ( ClassCastException cce ) {
throw new MappingException( "Bad identifier type: " + identifierType.getName() );
}
catch ( Exception e ) {
throw new MappingException( "Could not parse identifier unsaved-value: " + unsavedValue );
}
}
}
public static VersionValue getUnsavedVersionValue(
String versionUnsavedValue,
Getter versionGetter,
VersionType versionType,
Constructor constructor) {
if ( versionUnsavedValue == null ) {
if ( constructor!=null ) {
Object defaultValue = versionGetter.get( instantiate(constructor) );
// if the version of a newly instantiated object is not the same
// as the version seed value, use that as the unsaved-value
return versionType.isEqual( versionType.seed( null ), defaultValue ) ?
VersionValue.UNDEFINED :
new VersionValue( defaultValue );
}
else {
return VersionValue.UNDEFINED;
}
}
else if ( "undefined".equals( versionUnsavedValue ) ) {
return VersionValue.UNDEFINED;
}
else if ( "null".equals( versionUnsavedValue ) ) {
return VersionValue.NULL;
}
else if ( "negative".equals( versionUnsavedValue ) ) {
return VersionValue.NEGATIVE;
}
else {
// this should not happen since the DTD prevents it
throw new MappingException( "Could not parse version unsaved-value: " + versionUnsavedValue );
}
}
}