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From Chris Lamey <cla...@localmatters.com>
Subject Re: How can I change datasource connect info on the fly w/iBATIS and Spring?
Date Tue, 22 May 2007 15:19:01 GMT
Hello,

I also use Spring's DataSource txn mgr with this setup (in fact, I think
the Spring SqlMapClient can't use the iBATIS txn mgr).

My transactions are contained in a single Thread hitting a single
DataSource within an invocation of a method of my API.  A Thread will
likely end up hitting multiple DataSources over time, but that
ThreadLocal variable will be set upon entry into any API method for the
life of that method.

The Spring DataSource txn mgr essentially watches Threads hitting
DataSources, it really doesn't care how they come in.  There is no
difference to the txn mgr between calls from a normal SqlMapClient and
the RoutableSqlMapClient.  They're just method calls coming into the
DataSource on a per-Thread basis.  Spring basically opens a transaction
upon a Thread's entry into my API (more or less), the txn mgr then
batches up all the SQL generated, and when the Thread leaves the API the
txn mgr commits it all.

Cheers,
Chris

On Tue, 2007-05-22 at 14:12 +0200, tran duc trung wrote:
> I have not yet tested your solution, but how about the integration
> with Spring Transaction Manager? 
> We do not have IbatisTransactionManager in Spring but have to use
> DataSourceTransactionManager which is not notified when datasource
> change. 
> 
> 2007/4/13, Chris Lamey <clamey@localmatters.com>:
>         Yea, Spring has a new AbstractRoutingDataSource that can route
>         to a
>         different datasource based on a ThreadLocal.  The problem is
>         that the
>         iBATIS SqlMapClient doesn't know the datasource isn't the same
>         between 
>         calls, so your caching gets horked.
>         
>         Based on the AbstractRoutingDataSource idea, I wrote a
>         RoutingSqlMapClient that implements the ExtendedSqlMapClient
>         interface
>         and gets wired up in Spring like this:
>         
>         <bean id="sqlMapClient"
>             class="com.localmatters.bo.core.util.RoutingSqlMapClient">
>             <property name="targetSqlMapClients">
>             <map
>         key-type="com.localmatters.bo.core.commons.VendorTypes ">
>                 <entry key="VendorOne"
>         value-ref="vendorOneSqlMapClient"/>
>                 <entry key="VendorTwo"
>         value-ref="vendorTwoSqlMapClient"/>
>                 <entry key="VendorThree"
>         value-ref="vendorThreeSqlMapClient"/> 
>             </map>
>             </property>
>         </bean>
>         
>         Each of the "vendorXXXSqlMapClient" beans has its own
>         datasource and
>         transaction handling.  The "sqlMapClient" bean is then set on
>         all my 
>         DAOs.
>         
>         Then have a class, VendorContextHolder, that sets a
>         ThreadLocal
>         variable that is then used by the RoutableSqlMapClient as a
>         key in the
>         targetSqlMapClients Map.  My entry points into the API then
>         use a method 
>         parameter to set the ThreadLocal for the that thread for the
>         remainder
>         of the call.
>         
>         It's working well so far, everything works as
>         expected.  Transactions
>         are handled correctly and there's been no thread stomping. 
>         
>         I don't know if it'll work for you because your datasources
>         have to be
>         known in advance and it sounds like yours may not be.
>         
>         Cheers,
>         Chris
>         
>         On Fri, 2007-04-13 at 12:34 -0600, Larry Meadors wrote: 
>         > You could implement a custom datasource and datasource
>         factory to
>         > switch it on the fly, but I think you'd have troubles with
>         things like
>         > caching, etc.
>         >
>         > A safer implementation would have two sql map clients - one
>         per 
>         > datasource that you swapped instead.
>         >
>         > Larry
>         >
>         >
>         > On 4/13/07, Paul Sanders <tendancer@gmail.com> wrote:
>         > >
>         > > One of the characteristics of my application is that the
>         datasource 
>         > > connection information can be supplied by the user, and I
>         wonder if anyone
>         > > has any advice on how to handle that?
>         > >
>         > > Currently I define a datasource in my applicationcontext
>         with default 
>         > > information (my test db) and specify my BanPolicyDAO
>         object, letting Spring
>         > > inject the datasource. All works well with my new
>         BanPolicy configuration
>         > > (that you've all seen over and over this week!). 
>         > >
>         > > I searched the archives for dealing with multiple
>         datasources but all the
>         > > responses seemed to be in the case when you knew the
>         connection info in
>         > > advance. In my case I need to create a new datasource on
>         the fly, or be able 
>         > > to change the settings of the existing one. So far my
>         efforts haven't worked
>         > > - the DAO only ever uses the original connection info.
>         > >
>         > > Anyone tried this, or have have any thoughts on the best
>         way to do it? 
>         > >
>         > > Cheers
>         > >
>         > > Paul
>         > > --
>         > > View this message in context:
>         http://www.nabble.com/How-can-I-change-datasource-connect-info-on-the-fly-w-iBATIS-and-Spring--tf3573169.html#a9983995
>         > > Sent from the iBATIS - User - Java mailing list archive at
>         Nabble.com.
>         > >
>         > >
>         
> 

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