The default data source in WildFly 8.1 is configured with the H2 database engine. There are several options available for a database. The top four most commonly used relational databases are Oracle database, MySQL database, SQL Server, and PostgreSQL Server. Oracle database and SQL Server are designed for enterprise level applications and are not open source. Oracle database offers more features to facilitate system and data maintenance. It also offers features to prevent system and data failure as compared to SQL Server. MySQL and PostgreSQL are open source databases with comparable features and designed primarily for small scale applications. We will use MySQL database. Some of the reasons to choose MySQL are discussed at http://www.mysql.com/why-mysql/topreasons.html.
We will configure a datasource with the MySQL database for use in the EJB 3.x application for object/relational mapping. Use the following steps to configure a datasource:
- First, we need to create a module for MySQL database. For the MySQL module, create a module.xml file in the
%JBOSS_HOME%/modules/mysql/maindirectory; themysql/mainsubdirectory is also to be created. The module.xml file is listed in the following code snippet:<module xmlns="urn:jboss:module:1.1" name="mysql" slot="main"> <resources> <resource-root path="mysql-connector-java-5.1.33-bin.jar"/> </resources> <dependencies> <module name="javax.api"/> </dependencies> </module> - Copy the
mysql-connector-java-5.1.33-bin.jar(MySQL JDBC JAR) file fromC:Program Files (x86)MySQLConnector.J 5.1to the%JBOSS_HOME%/modules/mysql/maindirectory. The MySQLmysql-connector-javaJAR file version specified inmodule.xmlmust be the same as the version of the JAR file copied to the/modules/mysql/maindirectory. - Add a
<datasource/>definition for the MySQL database to the<datasources/>element and a<driver/>definition to the<drivers/>element in the%JBOSS_HOME%/standalone/configuration/standalone.xmlfile within the<subsystem xmlns="urn:jboss:domain:datasources:2.0"></subsystem>element. The<password/>tag in the<datasource/>configuration tag is the password configured when the MySQL database is installed. The datasource class for the MySQL driver is aXAdatasource, which is used for distributed transactions:<subsystem xmlns="urn:jboss:domain:datasources:2.0"> <datasources> <datasource jndi-name="java:jboss/datasources/MySQLDS" pool-name="MySQLDS" enabled="true" use-java-context="true"> <connection-url>jdbc:mysql://localhost:3306/test</connection-url> <driver>mysql</driver> <pool> <min-pool-size>10</min-pool-size> <max-pool-size>20</max-pool-size> <prefill>true</prefill> </pool> <security> <user-name>root</user-name> <password>mysql</password> </security> </datasource> <drivers> <driver name="mysql" module="mysql"> <driver-class>com.mysql.jdbc.Driver</driver-class> <xa-datasource-class>com.mysql.jdbc.jdbc2.optional.MysqlXADataSource</xa-datasource-class> </driver> </drivers> </datasources> </subsystem> - If the server is running after modifying the standalone.xml configuration file, restart WildFly 8.x server. The MySQL datasource gets deployed. To start or restart the WildFly server, double-click on the
C:wildfly-8.1.0.Finalinstandalonebatch file. - Log in to the WildFly 8 Administration Console with the URL:
http://localhost:8080. Click on Administration Console, as shown in the following screenshot:
- In the login dialog box, specify the username and password for the user added with the add-user.bat script.
- Select the Runtime tab in Administration Console. The MySQL datasource is listed as deployed in Datasources Subsystems, as shown in the following screenshot. Click on Test Connection to test the connection:
- If a connection with the MySQL database is established, a Successfully created JDBC connection message will get displayed:
In the next section, we will create entities for the EJB 3.x application.