gistfile1.java

import org.junit.AfterClass;
import org.junit.BeforeClass;
import org.junit.runner.RunWith;
import org.junit.runners.Suite;
import org.junit.runners.Suite.SuiteClasses;

@RunWith(Suite.class)
@SuiteClasses({Test1.class,Test2.class})
public class ITTestSuite{
    private static final String IT_PERSISTANCE_UNIT = "it-persistence-unit";
    private static final String JDBC_DRIVER = "org.apache.derby.jdbc.EmbeddedDriver";
    private static final String DB_URL = "jdbc:derby:memory:testDB;create=true";

    static EntityManagerFactory emf;
    static EntityManager em	

    @BeforeClass
    public static void setUp(){
        System.out.println("set up database");
	// 1. may this step is not required(to check it)
	try {
            Class.forName(JDBC_DRIVER); 
            DriverManager.getConnection(DB_URL).close();
        } catch (Exception ex) {
            ex.printStackTrace();
            fail("Exception during database startup.");
        }

	// 2. create EntityManager
	emf = Persistence.createEntityManagerFactory(mPersistenceUnit);
    	em = emf.createEntityManager();
    }

    @AfterClass
    public static void tearDown(){
	em.close();
	emf.close();
        System.out.println("tear down dababase");
    }
}


public class Test1{
    
    @Test
    publicvoid testSomething(){
        EntityTransaction transaction = em.getTransaction();
	transaction.begin();
	ITTestSuite.em.persist( /*some entity*/ );
	...
	ITTestSuite.em.merge( /*some entity*/ );
	// check that data has been persisted
	assertTrue(...);
	transaction.commit();	
    }
}