JBoss 7和EJB3 | 我应该在哪里定义数据源

Question

I'm new to Jboss and I don't understand where should I define the database connection data like url, username, password etc..

Here is my multimodule project:

app-root
    app-api
      - src
      - pom.xml

    app-ear
      - src
      - pom.xml

    app-ejb
      - src
      - pom.xml

    pom.xml

My persinstence.xml located unter app-root/app-ejb/src/main/config/default/META-INF/persistence.xml

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="1.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd">

    <persistence-unit name="ejb3_jpa_myapp_pu" transaction-type="JTA">
        <description>Jboss Test application</description>
        <provider>org.hibernate.ejb.HibernatePersistence</provider>
        <jta-data-source>java:jdbc/MyApp</jta-data-source>

        <properties>
            <property name="hibernate.dialect" value="org.hibernate.dialect.PostgreSQLDialect" />
            <property name="hibernate.hbm2ddl.auto" value="none" />
            <property name="hibernate.show_sql" value="true" />
        </properties>
    </persistence-unit>

</persistence>

And finaly my simple Service:

@Stateless
@Remote(IService.class)
public class ServiceImpl implements IService{

    @PersistenceContext(unitName = "ejb3_jpa_myapp_pu")
    private EntityManager em;

    @Override
    public void doSomeJob() {
        // [...]
    }
}

I know I have to define the database connection properties but where can I do that?

Answer 1

You need to define the data source in the standalone XML file that your JBoss instance is using. JBoss does not ship with database drivers so there are two steps:

1) Create a JBoss module for the database drivers (eg MySQL, Oracle, Postgres etc)

2) Create the datasource definition

Step 1) needs only to be done once, ie many MySQL datasources can use the same MySQL JBoss module.

Step 2) An example datasource configuration for MySQL would be:

<datasources>
   <datasource jndi-name="java:jboss/datasources/MySqlDS" pool-name="MySqlDS">
      <connection-url>jdbc:mysql://localhost:3306/EJB3</connection-url>
         <driver>com.mysql</driver>
      <transaction-isolation>TRANSACTION_READ_COMMITTED</transaction-isolation>
      <pool>
        <min-pool-size>10</min-pool-size>
        <max-pool-size>100</max-pool-size>
        <prefill>true</prefill>
      </pool>
      <security>
        <user-name>test</user-name>
        <password>test</password>
      </security>
      <statement>
        <prepared-statement-cache-size>32</prepared-statement-cache-size>
        <share-prepared-statements/>
      </statement>
    </datasource>
    <drivers>
      <driver name="com.mysql" module="com.mysql">
        <xa-datasource-class>com.mysql.jdbc.jdbc2.optional.MysqlXADataSource</xa-datasource-class>
      </driver>
    </drivers>
</datasources>

The above can be automated using the JBoss CLI. Also creating the JBoss modules can also be automated for example using the smartics-jboss-modules-maven-plugin see Generate an xml file with all dependencies with maven for more info.