Testing Java EE 6 with Arquillian (incl. JPA, EJB, Bean Validation and CDI)

For a very long time, I heard quite a lot of people saying good things about Arquillian. Whilst I have been reading articles around its use, I couldn’t really find one that covers some of the aspects that I find important, all in a single article. Granted, I haven’t looked hard enough.

Points that I would like to cover are:

  • The use of JPA. I simply use EclipseLink here,
  • The use of in-memory database,
  • The use of CDI injection,
  • The use of EJB, say local Stateless session bean,
  • The use of JSR-303 Bean Validation,
  • The use of (embedded) glassfish for integration testing.

It took me a while to gather information to get such project up and running. I thought I dedicate this post to help out those who’s got similar requirement.

So, what are we waiting for!? Let’s start!!!

Configure pom.xml

Of course, we need to configure out project to use Arquillian, and also use EclipseLink as the persistence provider. But, bear in mind that we also decide before that we want to use an in-memory database. You might want to include your dependency here, in this pom.xml. I, however, decide to use Derby, which is available in the standard Oracle Java SDK classpath.

Anyway, so the pom.xml would look like this:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" 
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 
		http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <artifactId>inout</artifactId>
        <groupId>id.co.dwuysan</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>

    <groupId>id.co.dwuysan</groupId>
    <artifactId>inout-ejb</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>ejb</packaging>

    <name>inout-ejb</name>

    <properties>
        <endorsed.dir>${project.build.directory}/endorsed</endorsed.dir>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <netbeans.hint.deploy.server>gfv3ee6</netbeans.hint.deploy.server>
    </properties>


    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.jboss.arquillian</groupId>
                <artifactId>arquillian-bom</artifactId>
                <version>1.0.0.Final</version>
                <scope>import</scope>
                <type>pom</type>
            </dependency>
        </dependencies>
    </dependencyManagement>
    
    <dependencies>
        <dependency>
            <groupId>org.eclipse.persistence</groupId>
            <artifactId>eclipselink</artifactId>
            <version>2.3.2</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.eclipse.persistence</groupId>
            <artifactId>javax.persistence</artifactId>
            <version>2.0.3</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.eclipse.persistence</groupId>
            <artifactId>org.eclipse.persistence.jpa.modelgen.processor</artifactId>
            <version>2.3.2</version>
            <scope>provided</scope>
        </dependency>

        <!-- test -->

        <dependency>
            <groupId>org.jboss.arquillian</groupId>
            <artifactId>arquillian-bom</artifactId>
            <version>1.0.3.Final</version>
            <type>pom</type>
        </dependency>
        <dependency>
            <groupId>org.glassfish.main.extras</groupId>
            <artifactId>glassfish-embedded-all</artifactId>
            <version>3.1.2.2</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.jboss.arquillian.container</groupId>
            <artifactId>arquillian-glassfish-embedded-3.1</artifactId>
            <version>1.0.0.CR3</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.jboss.arquillian.junit</groupId>
            <artifactId>arquillian-junit-container</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.11</version>
            <scope>test</scope>
        </dependency>

        <!-- environment requirement -->
        <dependency>
            <groupId>javax</groupId>
            <artifactId>javaee-api</artifactId>
            <version>6.0</version>
            <scope>provided</scope>
        </dependency>
    </dependencies>
    
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-surefire-plugin</artifactId>
                <version>2.12.4</version>
                <configuration>
                    <argLine>-XX:-UseSplitVerifier</argLine>
                    <systempropertyvariables>
                        <java.util.logging.config.file>
                        	${basedir}/src/test/resources/logging.properties
                        </java.util.logging.config.file>
                    </systempropertyvariables>
                    <systemProperties>
                        <property>
                            <name>derby.stream.error.file</name>
                            <value>target/derby.log</value>
                        </property>
                    </systemProperties>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>2.3.2</version>
                <configuration>
                    <source>1.7</source>
                    <target>1.7</target>
                    <compilerArguments>
                        <endorseddirs>${endorsed.dir}</endorseddirs>
                    </compilerArguments>
                    <showDeprecation>true</showDeprecation>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-ejb-plugin</artifactId>
                <version>2.3</version>
                <configuration>
                    <ejbVersion>3.1</ejbVersion>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-dependency-plugin</artifactId>
                <version>2.1</version>
                <executions>
                    <execution>
                        <phase>validate</phase>
                        <goals>
                            <goal>copy</goal>
                        </goals>
                        <configuration>
                            <outputDirectory>${endorsed.dir}</outputDirectory>


                            <silent>true</silent>
                            <artifactItems>
                                <artifactItem>
                                    <groupId>javax</groupId>
                                    <artifactId>javaee-endorsed-api</artifactId>
                                    <version>6.0</version>
                                    <type>jar</type>
                                </artifactItem>
                            </artifactItems>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
    <repositories>
        <repository>
            <id>java.net</id>
            <url>http://download.java.net/maven/</url>
        </repository>
        <repository>
            <id>JBOSS_NEXUS</id>
            <url>http://repository.jboss.org/nexus/content/groups/public</url>
        </repository>
        <repository>
            <url>http://download.eclipse.org/rt/eclipselink/maven.repo/</url>
            <id>eclipselink</id>
            <layout>default</layout>
            <name>Repository for library EclipseLink (JPA 2.0)</name>
        </repository>
    </repositories>
</project>

As shown in the XML above, the things we have done are:

  • Include the use of Arquillian, using embedded Glassfish
  • Include the use of EclipseLink
  • Set Derby props for later use, i.e. logging and location of the database created.
    • Create out ‘case’, i.e. our JPA, EJB, CDI

      Of course, we first start by creating a case, so that we can then later test it. I assume you are familiar with JPA, EJB, CDI. Hence, following are very quick glimpses of classes using these technology.

      JPA class, Outlet.java

      package id.co.dwuysan.inout.entity;
      
      // imports omitted
      
      @Entity
      @NamedQueries({
          @NamedQuery(
              name = Outlet.FIND_BY_NAME,
              query = "SELECT o FROM Outlet o WHERE o.name = :name")
      })
      public class Outlet implements Serializable {
          
          public static final String FIND_BY_NAME = "Outlet#FIND_BY_NAME";
          
          @Id
          @GeneratedValue(strategy = GenerationType.AUTO)
          private Long id;
          
          @Column(name = "code", length = 50, insertable = true, 
                  updatable = false, unique = true)
          @Size(message = "{dwuysan.nameSizeError}", min = 1, max = 50)
          @NotNull
          private String name;
      
          /* Accessors and mutators goes here */
      
          @Override
          public int hashCode() {
              // omitted
          }
      
          @Override
          public boolean equals(Object obj) {
              // omitted
          }
      }
      

      Persistence.xml

      <?xml version="1.0" encoding="UTF-8"?>
      <persistence version="2.0" 
      	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_2_0.xsd">
        <persistence-unit name="inoutPU" transaction-type="JTA">
          <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
          <jta-data-source>inoutDb</jta-data-source>
          <exclude-unlisted-classes>false</exclude-unlisted-classes>
          <properties>
            <property name="eclipselink.ddl-generation" value="drop-and-create-tables"/>
          </properties>
        </persistence-unit>
      </persistence>
      

      Then let’s add a producer method to supply our PersistenceContext, as well as our EJB that uses it.

      EntityManagerProducer.java

      package id.co.dwuysan.inout.util;
      
      import javax.enterprise.inject.Produces;
      import javax.persistence.EntityManager;
      import javax.persistence.PersistenceContext;
      
      public class EntityManagerProducer {
      
          @Produces
          @PersistenceContext
          private EntityManager em;
      }
      

      OutletService.java

      package id.co.dwuysan.inout.service;
      
      // imports omitted
      
      @Stateless
      @LocalBean
      public class OutletService {
      
          @Inject
          private EntityManager em;
          
          @Resource
          private Validator validator;
      
          public Outlet createOutlet(final String name) {
              final Outlet outlet = new Outlet();
              outlet.setName(name);
              final Set<ConstraintViolation<Outlet>> violations = this.validator.validate(outlet);
              if (!violations.isEmpty()) { throw new ConstraintViolationException(new HashSet<ConstraintViolation<?>>(violations)); }
              return this.em.merge(outlet);
          }
      
          public Outlet getOutlet(final String name) {
              final Query query = this.em.createNamedQuery(Outlet.FIND_BY_NAME);
              query.setParameter("name", name);
              try {
                  return (Outlet) query.getSingleResult();
              } catch (NoResultException e) {
                  return null;
              }
          }
      }
      

      Sets beans.xml and ValidationMessages.properties
      Don’t forget to:

      • add beans.xml under src/main/resources/META-INF, and
      • add ValidationMessages.properties under src/main/resources, and
      • configure your message dwuysan.nameSizeError=error message you like here

      Configure for testing purpose

      At this point, should you deploy, it should work. HOWEVER, that’s not our goal. We would like to get it working under Arquillian, using embedded Glassfish.

      Firstly, let’s prepare configuration for embedded glassfish, using Derby database. The file is glassfish-resources.xml. In my case, I simply put this file under a new directory, mainly for separation, i.e. src/test/resources-glassfish-embedded/glassfish-resources.xml.

      glassfish-resources.xml

      <?xml version="1.0" encoding="UTF-8"?>
      <!DOCTYPE resources PUBLIC
          "-//GlassFish.org//DTD GlassFish Application Server 3.1 Resource Definitions//EN"
          "http://glassfish.org/dtds/glassfish-resources_1_5.dtd">
      <resources>
          <jdbc-resource pool-name="ArquillianEmbeddedDerbyPool"
                         jndi-name="jdbc/arquillian"/>
          <jdbc-connection-pool name="ArquillianEmbeddedDerbyPool"
                                res-type="javax.sql.DataSource"
                                datasource-classname="org.apache.derby.jdbc.EmbeddedDataSource"
                                is-isolation-level-guaranteed="false">
              <property name="databaseName" value="target/databases/derby"/>
              <property name="createDatabase" value="create"/>
          </jdbc-connection-pool>
      </resources>
      

      It is quite self-explanatory. Just remember to configure the database to be created on target/databases/derby so that when you do mvn clean it will be cleaned.

      Next step, is to configure Arquillian to “recognise” this glassfish-resources.xml. To do this, add arquillian.xml under the src/test/resources directory.

      glassfish-resources.xml

      <?xml version="1.0" encoding="UTF-8"?>
      <arquillian xmlns="http://jboss.org/schema/arquillian"
                  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                  xsi:schemaLocation="http://jboss.org/schema/arquillian http://jboss.org/schema/arquillian/arquillian_1_0.xsd">
          <engine>
              <property name="deploymentExportPath">target/arquillian</property>
          </engine> 
          <container default="true" qualifier="glassfish">
              <configuration>
                  <property name="resourcesXml">src/test/resources-glassfish-embedded/glassfish-resources.xml</property>
              </configuration>
          </container>
      </arquillian>
      

      The next step is to prepare our persistence.xml. We already have one, but remember we need to supply the one which is in-memory, and make use of the jdbc connection provided by our embedded Glassfish (see glassfish-resources.xml above, which provide the jdbc-resource-pool under the JNDI name jdbc/arquillian. In my case, I named this test-persistence.xml, under src/test/resources

      test-persistence.xml

      <?xml version="1.0" encoding="UTF-8"?>
      <persistence version="2.0" 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_2_0.xsd">
          <persistence-unit name="inoutPU" transaction-type="JTA">
              <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
              <jta-data-source>jdbc/arquillian</jta-data-source>
              <exclude-unlisted-classes>false</exclude-unlisted-classes>
              <shared-cache-mode>ALL</shared-cache-mode>
              <properties>
                  <property name="javax.persistence.jdbc.driver" value="org.apache.derby.jdbc.EmbeddedDriver" />
                  <property name="javax.persistence.jdbc.url" value="jdbc:derby:target/databases/derby;create=true" />
                  <property name="eclipselink.ddl-generation" value="drop-and-create-tables" />
                  <property name="eclipselink.target-database" value="Derby"/>
                  <property name="eclipselink.ddl-generation" value="drop-and-create-tables"/>
                  <property name="eclipselink.debug" value="OFF"/>
                  <property name="eclipselink.weaving" value="static"/>
                  <!--<property name="eclipselink.logging.level" value="FINEST"/>-->
                  <property name="eclipselink.logging.level.sql" value="FINE"/>
                  <property name="eclipselink.logging.parameters" value="true"/>
                  <!--<property name="eclipselink.logging.level.cache" value="FINEST"/>-->
                  <property name="eclipselink.logging.logger" value="DefaultLogger"/>
              </properties>
          </persistence-unit>
      </persistence>
      

      When everything is ready, we are now ready to write our unit test, with Arquillian. In this case, it is best to test our service EJB, since that’s where we are going to use JPA, CDI, and the Validation.

      OutletServiceTest.java

      package id.co.dwuysan.inout.service;
      
      // imports omitted
      
      @RunWith(Arquillian.class)
      public class OutletServiceTest {    
          
          @Inject
          private OutletService outletService;
      
          @Deployment
          public static JavaArchive createTestArchive() {
              return ShrinkWrap.create(JavaArchive.class)
                      .addClass(Outlet.class)
                      .addClass(OutletService.class)
                      .addClass(EntityManagerProducer.class)
                      .addAsManifestResource("test-persistence.xml",
                      	ArchivePaths.create("persistence.xml"))
                      .addAsManifestResource("META-INF/beans.xml",
                      	ArchivePaths.create("beans.xml"))
                      .addAsResource("ValidationMessages.properties");
          }
          
          
          @Test
          public void testCreateOutlet() throws Exception {
              final String outletName = "Outlet 001";
              final Outlet outlet = this.outletService.createOutlet(outletName);
              Assert.assertNotNull(outlet);
      
              // check retrieval
              final Outlet retrievedOutlet = this.outletService.getOutlet(outletName);
              Assert.assertEquals(outlet.getName(), retrievedOutlet.getName());
          }
          
          @Test(expected = ConstraintViolationException.class)
          public void testCreateOutletWithEmptyName() throws Exception {
              try {
                  final Outlet outlet = this.outletService.createOutlet("");
              } catch (EJBException e) {             
                  final ConstraintViolationException cve = (ConstraintViolationException) e.getCause();
                  
                  Assert.assertEquals("Total error message should only be one",
                  	1, cve.getConstraintViolations().size());            
                  Assert.assertEquals("Message must be correct",
                  	"Name must be provided",
                  	cve.getConstraintViolations().iterator().next().getMessage());
                  throw cve;
              }
          }
      }
      

      In the above example, the first test is testing the successful case. Given a name, a retrieval should result in an Outlet entity return providing the same name as parameter. Underneath the surface though, if we look back at the body of the OutletService.java, we are actually testing:

      • Persistence (JPA), into the underlying Derby
      • EJB injected into this test/li>
      • PersistenceContext injected via Producer method (CDI)
      • Testing no validation violated
      • Testing our NamedQuery

      The second test is aimed to test that the message is interpolated correctly. Referring to what mentioned previously, for my error message, I have put the following entry in my ValidationMessages.properties:

      dwuysan.nameSizeError=Name must be provided
      

      So, we need to test that the message from Bean Validation in Outlet is interpolated correctly.

      Please pay attention to the second test. Notice that firstly, we are catching EJBException. That is because any runtime exception thrown inside an EJB will be wrapped into EJBException, hence the need to extract it via #getCause().

      So, there you go. You can now add more services and start your Arquillian test. Happy coding 🙂

      Future investigation

      Many Java EE application of course requires authentication and authorisation, which is generally done via JAAS. For example, using my simple example above, supposed that the service is to be modified to retrieve the outlets the current user has access to, then of course we need to get the current user’s identity. Generally, this is done via EJBContext.getCallerPrincipal(). I wonder how we can do this using Arquillian and embedded Glassfish.

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    Hollywood Principle – translated

    For as long as dependency injection gained its popularity (starting with Spring, then followed by Java EE, etc), people have always associated DI with Hollywood Principle – Don’t call us, we’ll call you.

    Yet, perhaps it’s just my own ignorance, I have never found any direct translation as to why dependency injection is “Don’t call us, we’ll call you”. Even during some interviews, I have heard quite a number of people being asked, What do you know about Hollywood Principle?. The answer generally follows the line of:

    • “It’s dependency injection, period”, or
    • “It’s like Spring where by your objects are instantiated with its dependencies, period”.

    I have never really found a satisfactory explanation, until today.

    Therefore, perhaps more for my own reference, with the hope that those who are as confused as I was previously would find this post beneficial, the best explanation I found is from one of the post by Andrew Binstock (2008). Following is one of the paragraphs I found from the author’s post that I paraphrased.

    “Dependency Injection was originally called Inversion of Control (IoC) because as opposed to the normal control sequence where an object finds the objects it depends on by itself, and then calls them, in IoC it is reversed. The dependencies are handed to the object when it’s created. This also illustrates the Hollywood Principle at work: Don’t call around for your dependencies, we (in this case the IoC container/runtime) will give them to you when we need you(Binstock 2008).

    Reference:

    Binstock, A, 2008, Binstock on Software: Excellent Explanation of Dependency Injection (Inversion of Control), accessed 22 March 2012.