RE: [Springframework-developer] Ibatis integration corrections needed

[Brandon G. <ma...@ph...>]

The issue here of setting the datasource still remains. If you set the
connection via the setUserConnection it doesn't take full advantage of
ibatis. However, it is possible to allow for Spring to be the iBatis
TransactionManager. You simply need to set up an EXTERNAL TransactionConf=
ig
to use in the TransactionManager. Please review my previous code. It show=
s
exactly how that is set. If you feel that iBatis may need to provide bett=
er
integrtion points for Spring to take advantage of... feel free to provide
suggestions.

Thanks,
Brandon Goodin
http://www.ibatis.com

-----Original Message-----
From: spr...@li...
[mailto:spr...@li...]On Behalf
Of j=FCrgen h=F6ller [werk3AT]
Sent: Saturday, May 29, 2004 11:53 AM
To: spr...@li...
Subject: Re: [Springframework-developer] Ibatis integration corrections
needed


Hi again, Brandon,

While I agree that Spring allows iBATIS users to choose between Spring's =
own
transaction management and iBATIS transaction management, this does not
necessarily affect the iBATIS support classes that we provide: Those clas=
ses
are specifically meant to integrate SQL Maps into Spring's resource and
transaction management, potentially sharing transactions with other data
access strategies within Spring (for example, plain JDBC or Hibernate).

As far as I understand, the SqlMapClient API already allows for simple
one-line operations when using its own resource and transaction managemen=
t.
So effectively, you don't need to use Spring's SqlMapClientTemplate in th=
at
scenario: Simply use the SqlMapClient instance directly. Of course, you c=
an
still use Spring's SqlMapClientFactoryBean to set up your SqlMapClient in
the application context, passing it to your DAOs via bean references.

A disadvantage that I see with direct SqlMapClient usage is that you have=
 to
deal with checked SQLExceptions that your DAOs throw. However, that's als=
o
the case with your iBATIS transaction demarcation code, so that will be
consistent throughout the application. The alternative is to use Spring's
resource and transaction management: throwing unchecked DataAccessExcepti=
ons
from DAOs (like SqlMapClientTemplate does), and unchecked
TransactionExceptions from transaction demarcation code (like Spring's
PlatformTransactionManager interface and declarative demarcation faciliti=
es
do).

So in the end, there are two choices for using Spring in combination with
iBATIS SQL Maps: either Spring resource and transaction management (->
coding your DAOs with SqlMapClientTemplate), or iBATIS resource and
transaction management (-> coding your DAOs with SqlMapClient directly). =
I
don't see a need to rework SqlMapClientTemplate here: Simply use
SqlMapClient directly in your scenario; you can still leverage all of
Spring's IoC facilities.

Juergen


________________________________

Von: spr...@li... im Auftrag von
Brandon Goodin
Gesendet: Sa 29.05.2004 07:42
An: spr...@li...
Betreff: RE: [Springframework-developer] Ibatis integration corrections
needed



Also, after some exploration I have discovered that Spring requires that =
the
Datasource be set via the <property name=3D"dataSource"> on the SqlMapDao=
s.
This is not good. What happens when someone wants to allow iBatis to mana=
ge
transactions on it's own? I think that the datasource requirement needs t=
o
be removed. Setting the datasource via spring should be optional not
required.



Brandon Goodin

http://www.ibatis.com



________________________________

From: spr...@li...
[mailto:spr...@li...] On Behalf =
Of
Brandon Goodin
Sent: Friday, May 28, 2004 6:57 PM
To: spr...@li...
Subject: [Springframework-developer] Ibatis integration corrections neede=
d



Greetings,



My name is Brandon Goodin. I am committer on the iBatis project. As I've =
had
time recently I've become increasingly more familiar with the Spring prod=
uct
and began to explore the code base. I specifically have examined the iBat=
is
integration and noticed a problem in how the datasource is being set.



In the  SqlMapClientTemplate the execute method is using
session.setUserConnection(con);. Setting the connection using
setUserConnection on the SqlMapSession will not take full advantage of
ibatis functionality (i.e. lazy loading will not work).



The short explanation is that Spring needs to set the the Datasource via =
the
TransactionConfig which is stored in the TransactionManager. The
TransactionManager needs to be set via the SqlMapExecutorDelegate of the
SqlMapClient. The TransactionManager contains the TransactionConfig which
contains the datasource and various other pertinent config info for
transactions.



Following is a chunk from the XmlSqlMapClientBuilder that demonstrates ho=
w
the datasource should be configured in ibatis:


---- start code ---
TransactionManager txManager =3D null;
try {
errorCtx.setMoreInfo("Check the transaction manager type or class.");
TransactionConfig config =3D (TransactionConfig) Resources.instantiate(ty=
pe);
config.setDataSource(dataSource);
config.setMaximumConcurrentTransactions(client.getDelegate().getMaxTransa=
cti
ons());
errorCtx.setMoreInfo("Check the transactio nmanager properties or
configuration.");
config.initialize(initProperties);
errorCtx.setMoreInfo(null);
txManager =3D new TransactionManager(config);
} catch (Exception e) {
if (e instanceof SqlMapException) {
throw (SqlMapException) e;
} else {
throw new SqlMapException("Error initializing TransactionManager. Could n=
ot
instantiate TransactionConfig. Cause: " + e, e);
}
}

client.getDelegate().setTxManager(txManager);

--- end code ---



From what I can tell Spring allows for iBatis users to take advantage of =
the
iBatis transaction facilities if they choose (i.e. avoid using spring
transaction management if they so choose). So, the only thing that is lef=
t
is for Spring to use the proper implementation of the TransactionConfig
(com.ibatis.sqlmap.engine.transaction.external.ExternalTransactionConfig)
for the configuration of the datasource. The ExternalTransactionConfig wi=
ll
allow for Spring to manage the commit and rollback functionality without
losing valuable functionality in iBatis (lazy loading).



I'd be happy to work on the Spring code base if you would like or provide
you with more insight if you need. Let me know.



Thanks,

Brandon Goodin

http://www.ibatis.com <http://www.ibatis.com/>





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