z2-Environment

h1. Using a Spring configured full-blown transaction manager across modules in Z2

As does [[Sample-jta-plain]], so does this sample demonstrate how to use Z2 with the Atomikos transaction manager. In this case however, we choose to use the Spring framework to configure the transaction manager and enable re-use using Z2's support for modular Spring applications (see also [[How to Spring]]).

The Wiki page [[How_to_TransactionManager]] explains the general principles behind transaction handling in Z2.

This sample is stored in "z2-samples.jta-spring":http://redmine.z2-environment.net/projects/z2-samples/repository/z2-samples-jta-spring. It implements exactly the same scenario as [[Sample-spring-hibernate]] with the exception of not using the built-in JTA implementation.

h2. Prerequisites

{{include(Java Version Requirements)}}

You need to run Java DB as network server on localhost. This is explained next.

The application will create a database "z2-samples"

{{include(How to run Java db)}}

h2. Running the sample

This sample is run as explained in [[How to run a sample]]. The 5 minutes version:

<pre><code class="ruby">

mkdir install

cd install 

git clone -b v2.5 http://git.z2-environment.net/z2-base.core

git clone -b v2.5 http://git.z2-environment.net/z2-samples.jta-spring

# on Linux / Mac OS:

cd z2-base.core/run/bin

./gui.sh

# on Windows:

cd z2-base.core\run\bin

gui.bat

</code></pre>

h2. Verifying

When everything is up, go to http://localhost:8080/jta-spring. You see something like this: 

!jta-spring-thingies.png!

tra

And indeed, it's the same database we use elsewhere.

h2. Now to the point...

This sample illustrates how to use a third-party transaction manager, the Atomikos implementation in this case, in a modular application as indicated in  [[How_to_TransactionManager]]. This in conjunction with Spring resulting in a full-blown, highly adaptable and completely modular environment, scalable in deployment and development.

Unlike [[Sample-jta-plain]], Atomikos configuration and set up of transaction manager and user transaction is done by Spring. This may be perceived a more consistent approach by Spring users.

Instead of invoking the JTA Transaction Manager interface directly, transaction demarcation is done using Spring's \@Transactional annotation (in the "Controller":https://redmine.z2-environment.net/projects/z2-samples/repository/z2-samples-jta-spring/revisions/master/entry/com.zfabrik.samples.jta-spring.web/java/src.impl/com/zfabrik/samples/jta_spring/web/ControllerFilter.java). Note that Spring transaction de-marcation cannot be used with direct transaction manager usage at the same time (as Spring keeps additional context).