Author: Mike Musgrove
Level: Intermediate
Technologies: EJB, BMT
Summary: The bmt
quickstart demonstrates Bean-Managed Transactions (BMT), showing how to manually manage transaction demarcation while accessing JPA entities.
Target Product: WildFly
Source: https://github.com/wildfly/quickstart/
The bmt
quickstart demonstrates how to manually manage transaction demarcation while accessing JPA entities in WildFly Application Server.
On occasion, the application developer requires finer grained control over the lifecycle of JTA transactions and JPA Entity Managers than the defaults provided by the Java EE container. This example shows how the developer can override these defaults and take control of aspects of the lifecycle of JPA and transactions.
When you run this example, you will be provided with a Use bean managed Entity Managers
checkbox. * If you check the checkbox, it shows the developer responsibilities when injecting an Entity Manager into a managed (stateless) bean. * If you uncheck the checkbox, shows the developer responsibilities when using JPA and transactions with an unmanaged component.
WildFly ships with H2, an in-memory database written in Java. This example shows how to transactionally insert key value pairs into the H2 database and demonstrates the requirements on the developer with respect to the JPA Entity Manager.
Note: This quickstart uses the H2 database included with WildFly Application Server 11. It is a lightweight, relational example datasource that is used for examples only. It is not robust or scalable, is not supported, and should NOT be used in a production environment!
Note: This quickstart uses a *-ds.xml
datasource configuration file for convenience and ease of database configuration. These files are deprecated in WildFly and should not be used in a production environment. Instead, you should configure the datasource using the Management CLI or Management Console. Datasource configuration is documented in the Configuration Guide for WildFly Application Server.
NOTE: A Java EE container is designed with robustness in mind, so you should carefully analyze the scalabiltiy, concurrency, and performance needs of your application before taking advantage of these techniques in your own applications.
The application this project produces is designed to be run on WildFly Application Server 11 or later.
All you need to build this project is Java 8.0 (Java SDK 1.8) or later and Maven 3.3.1 or later. See Configure Maven for WildFly 11 to make sure you are configured correctly for testing the quickstarts.
In the following instructions, replace WILDFLY_HOME
with the actual path to your WildFly installation. The installation path is described in detail here: Use of WILDFLY_HOME and JBOSS_HOME Variables.
For Linux: WILDFLY_HOME/bin/standalone.sh
For Windows: WILDFLY_HOME\bin\standalone.bat
mvn clean install wildfly:deploy
This will deploy target/bmt.war
to the running instance of the server.
The application will be running at the following URL: http://localhost:8080/bmt/.
You will be presented with a simple form for adding key/value pairs and a checkbox to indicate whether the updates should be executed using an unmanaged component. Effectively this will run the transaction and JPA updates in the servlet, not session beans. If the box is checked then the updates will be executed within a session bean method.
Note: You will see the following warnings in the server log. You can ignore these warnings.
WFLYJCA0091: -ds.xml file deployments are deprecated. Support may be removed in a future version.
HHH000431: Unable to determine H2 database version, certain features may not work
mvn wildfly:undeploy
You can also start the server and deploy the quickstarts or run the Arquillian tests from Eclipse using JBoss tools. For general information about how to import a quickstart, add a WildFly server, and build and deploy a quickstart, see Use JBoss Developer Studio or Eclipse to Run the Quickstarts.
If you want to debug the source code of any library in the project, run the following command to pull the source into your local repository. The IDE should then detect it.
mvn dependency:sources