How should I test an EJB 3.1 which gets an instance of EntityManager injected?
A possible EJB:
@Stateless
@LocalBean
public class CommentService {
@PersistenceContext
private EntityManager em;
public List<Comment> findAll() {
TypedQuery<Comment> query = em.createNamedQuery(
Comment.FIND_ALL, Comment.class
);
return query.getResultList();
}
}
A possible test:
@Test
public void testFindAll() {
List<Comment> all = service.findAll();
Assert.assertEquals(8, all.size());
}
I am only using GlassFish 3.1 and Eclipse Indigo for Java EE Developers. I already tried things like that:
@Before
public void setUp() throws Exception {
ejbContainer = EJBContainer.createEJBContainer();
service = (CommentService) ejbContainer.getContext()
.lookup("java:global/classes/CommentService");
}
But all I got was:
javax.ejb.EJBException:
No EJBContainer provider available: no provider names had been found.
The accepted answer requires mocking a lot of code, including the persistence layer. Use an embedded container to test the actual beans, instead; otherwise, mocking the persistence layer results in code that barely tests anything useful.
Use a session bean with an entity manager that references a persistence unit:
@Stateless
public class CommentService {
@PersistenceContext(unitName = "pu")
private EntityManager em;
public void create(Comment t) {
em.merge(t);
}
public Collection<Comment> getAll() {
Query q = em.createNamedQuery("Comment.findAll");
Collection<Comment> entities = q.getResultList();
return entities;
}
}
The entity bean:
@Entity
@NamedQueries({@NamedQuery(name = "Comment.findAll", query = "select e from Comment e")})
public class Comment implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
}
This persistence unit is defined in the persistence.xml
file as follows:
<persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
<persistence-unit name="pu" transaction-type="JTA">
<provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
<class>org.glassfish.embedded.tempconverter.Comment</class>
<properties>
<property name="eclipselink.ddl-generation" value="drop-and-create-tables"/>
</properties>
</persistence-unit>
</persistence>
The transaction type must be JTA
.
Then write a test that creates and destroys the EJB container (GlassFish embedded container):
public class CommentTest extends TestCase {
private Context ctx;
private EJBContainer ejbContainer;
@BeforeClass
public void setUp() {
ejbContainer = EJBContainer.createEJBContainer();
System.out.println("Opening the container" );
ctx = ejbContainer.getContext();
}
@AfterClass
public void tearDown() {
ejbContainer.close();
System.out.println("Closing the container" );
}
public void testApp() throws NamingException {
CommentService converter = (CommentService) ctx.lookup("java:global/classes/CommentService");
assertNotNull(converter);
Comment t = new Comment();
converter.create(t);
t = new Comment();
converter.create(t);
t = new Comment();
converter.create(t);
t = new Comment();
converter.create(t);
Collection<Comment> ts = converter.getAll();
assertEquals(4, ts.size());
}
}
Next, add two dependencies (such as to a Maven POM):
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.8.2</version>
<scope>test</scope>
<type>jar</type>
</dependency>
<dependency>
<groupId>org.glassfish.main.extras</groupId>
<artifactId>glassfish-embedded-all</artifactId>
<version>3.1.2</version>
<scope>compile</scope>
</dependency>
Having the dependencies, session and entity bean, persistence file, test files implemented exactly as shown, then the test(s) should pass. (The examples on the Internet are woefully inadequate.)