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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Hi,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>So in response to my previous mail, I’ve
applied a short fix for IdentifierGeneratorFactory to enable custom types to be
used for auto-generated keys.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Here’s IdentifierGeneratorFactory’s
modified public static Serializable get(….) method, which was extended
based on the 3.3.1.GA release:<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> public static
Serializable get(ResultSet rs, Type type) throws SQLException,
IdentifierGenerationException {<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> <u>Class</u>
clazz = type.getReturnedClass();<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> if ( clazz
== Long.class ) {<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> return
new Long( rs.getLong( 1 ) );<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> }<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> else if (
clazz == Integer.class ) {<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> return
new Integer( rs.getInt( 1 ) );<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> }<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> else if (
clazz == Short.class ) {<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> return
new Short( rs.getShort( 1 ) );<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> }<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> else if (
clazz == String.class ) {<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> return
rs.getString( 1 );<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> }<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> else {<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> // try
to instantiate the custom type through reflection<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> try {<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>
Constructor<?>[] constructors =
type.getReturnedClass().getConstructors();<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> for
(Constructor<?> constructor : constructors)<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> {<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>
Class<?>[] parameterTypes = constructor.getParameterTypes();<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> if
(parameterTypes.length == 1)<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> if (Long.class.equals(parameterTypes[0]))<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> return
(Serializable) constructor.newInstance(rs.getLong(1));<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> else if
(Integer.class.equals(parameterTypes[0]))<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>
return (Serializable) constructor.newInstance(rs.getInt(1));<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>
else if (Short.class.equals(parameterTypes[0]))<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>
return (Serializable) constructor.newInstance(rs.getShort(1));<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>
else if (String.class.equals(parameterTypes[0]))<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>
return (Serializable) constructor.newInstance(rs.getString(1));<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> }<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> } catch (Throwable t) {<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> throw new
IdentifierGenerationException( "Error instantiating custom type: " +
type + " with value class: " + type.getReturnedClass(), t );<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> }<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> <o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> throw new
IdentifierGenerationException( "Supplied custom type doesn't have a
1-argument constructor which could take either long, integer, short or string:
" + type.getReturnedClass().getName() );<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> }<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'> }<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>So this would allow you to use any class for an
auto-generated ID, for example:<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>public</span></font><font size=2
face=Arial><span style='font-size:10.0pt;font-family:Arial'> class
UniqueInteger implements Serializable {<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> private Integer internal;<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> <o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> public UniqueInteger()<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> {<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> }<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> <o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> public UniqueInteger(Integer
internal)<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> {<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'> this.internal = internal;<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'> }<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>}<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>The only requirement is that it should have a 1-argument
constructor that can take either long, integer, short or string.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Which I think makes sense.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Please submit your feedback and thoughts on this!<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=HU style='font-size:10.0pt;
font-family:Arial'>--Dávid</span></font><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<div>
<div class=MsoNormal align=center style='text-align:center'><font size=3
face="Times New Roman"><span style='font-size:12.0pt'>
<hr size=2 width="100%" align=center tabindex=-1>
</span></font></div>
<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> Nádaski Dávid
[mailto:david@aquilanet.hu] <br>
<b><span style='font-weight:bold'>Sent:</span></b> Wednesday, December 10, 2008
7:23 AM<br>
<b><span style='font-weight:bold'>To:</span></b> '<st1:PersonName w:st="on">hibernate-dev@lists.jboss.org</st1:PersonName>'<br>
<b><span style='font-weight:bold'>Subject:</span></b> Using custom types for
auto-generated id columns</span></font><o:p></o:p></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Hi,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>I was trying to use a custom type for which there was a
valid Type implementation, and have run into the following error:<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>28240 [http-8080-1] ERROR org.hibernate.event.def.AbstractFlushingEventListener
- Could not synchronize database state with session<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>org.hibernate.id.IdentifierGenerationException: this id
generator generates long, integer, short or string<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'> at
org.hibernate.id.IdentifierGeneratorFactory.get(IdentifierGeneratorFactory.java:116)<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>etc.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>I’m using MySQL.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Looking at the source, it seems like Hibernate doesn’t
support anything other than a “long, integer, short or string”.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>In the parameters of
IdentifierGeneratorFactory.get(….), there’s one called “Type
type”. This gets mapped correctly to my custom, but since that’s
none of those “primitive” types, I get the error – but since
the Type information is available, it could easily be used to map say a String
using Type.nullSafeGet(ResultSet rs, String[] names, SessionImplementor
session, Object owner), since we have both the ResultSet and the Type parameter
available in IdentifierGeneratorFactory.get(ResultSet rs, Type type). So then,
the proper custom type could be returned if it indeed supports this kind of
mapping (which is by definition it’s job).<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>So I propose a patch should be made to
IdentifierGeneratorFactory that would enable the use of custom types for
identity-generated columns.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>It’s possible that I’m missing something, in that
case please point out my error.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Upon request, I think I can supply the appropriate patch,
although it seems easy to code.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Thanks,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>David<o:p></o:p></span></font></p>
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