Hello everyone Itry to inject a entitymanger using @PersistenceContext but all that i get is a entitymanger that is null anyone who had the same problem? *file: META-INF/persistence.xml* <persistence xmlns="http://java.sun.com/xml/ns/persistence" <http://java.sun.com/xml/ns/persistence>     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" <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" <http://java.sun.com/xml/ns/persistencehttp://java.sun.com/xml/ns/persiste...     version="1.0">     <persistence-unit name="groepsadmin" transaction-type="JTA"> <jta-data-source>java:jboss/datasources/GroepsAdminDS</jta-data-source> <class>be.scoutsengidsenvlaanderen.login.importer.LidEntity</class>         <properties>             <property name="jboss.as.jpa.managed" value="true"/>             <property name="hibernate.show_sql" value="true"/>             <property name="hibernate.format_sql" value="true"/>             <property name="hibernate.dialect" value="org.hibernate.dialect.PostgreSQLDialect"/>         </properties>     </persistence-unit> </persistence> *file: standelone.xml* <datasource jta="true" jndi-name="java:jboss/datasources/GroepsAdminDS" pool-name="GroepsAdminDS" use-java-context="true" use-ccm="true"> <connection-url>jdbc:postgresql://URL</connection-url>         <driver>postgresql</driver>         <validation>             <check-valid-connection-sql>select 1</check-valid-connection-sql> <background-validation>true</background-validation> <background-validation-millis>10000</background-validation-millis>         </validation>         <security>             <user-name>username</user-name>             <password>pass<password>         </security>     </datasource>     <drivers>         <driver name="h2" module="com.h2database.h2"> <xa-datasource-class>org.h2.jdbcx.JdbcDataSource</xa-datasource-class>         </driver>         <driver name="postgresql" module="org.postgresql"> <xa-datasource-class>org.postgresql.xa.PGXADataSource</xa-datasource-class>         </driver>     </drivers> </datasources> *file: class waar ik de entitymanger wil gebruiken* @Stateless public class Leden {     @PersistenceContext(name = "groepsadmin")     private EntityManager entityManager;     public Leden(EntityManager em) {         if (entityManager == null){             System.out.println("EntityManger is null");         }     } -- Met vriendelijke scouts- en gidsengroeten, <https://www.scoutsengidsenvlaanderen.be> *Daan Zwaenepoel | Jobstudent - Groepsadministratie* <https://www.scoutsengidsenvlaanderen.be/het-uitzicht> *Scouts en Gidsen Vlaanderen vzw* dz(a)scoutsengidsenvlaanderen.be <mailto:dz@scoutsengidsenvlaanderen.be>