Clearing the context to avoid out of memory when using JUnit test

[Jonathan Alvarsson]

I use JUnit tests from within Eclipse to test my code. My problem is that each test sets up a new applicationContext and don't seem to be able to get rid of it by just nulling the reference. So I quickly get a heck of a lot of instances of objects and I run out of memory. (Everything becomes REALLY slow) Is there a clever way to get rid of all Spring objects from memory when I am done with a test and goes on to the next one?

// Jonathan

[Marten Deinum]

Are you using your own test mechanism or use the test classes provided by Spring? I strongly suggest you use the latter.

[Jonathan Alvarsson]

Are you using your own test mechanism or use the test classes provided by Spring? I strongly suggest you use the latter.

Are there test classes provided by Spring? Will they help with this? my tests looks a little bit like this:

package net.bioclipse.lis.tests.daos;

import java.util.ArrayList;
import java.util.List;

import org.junit.Test;

import static org.junit.Assert.*;

import net.bioclipse.lis.genericDAO.IUserDAO;
import net.bioclipse.lis.pojos.User;

/**
 * Tests all the functionality of the <code>UserDAO</code>
 * 
 * @author jonathan
 *
 */
public class UserDAOTest extends AbstractGenericDAOTest {
	
	public IUserDAO getDAO(){
		return (IUserDAO)dao;
	}
	
	public UserDAOTest() {
		super("userDAO");
	}

	/**
	 * Test method for {@link net.bioclipse.lis.daos.UserDAO#delete(long)}.
	 */
	@Test
	public void testDelete() {
		User user   = User.createUser("Delete Tester");
		assertFalse(user.isDeleted());
		getDAO().save(user);
		
		session.flush();
		session.clear();
		
		getDAO().delete(user.getId());
		
		session.flush();
		session.clear();
		
		User deleted = getDAO().getById(new Long(user.getId()));
		assertTrue(deleted.isDeleted());
	}

	/**
	 * Test method for {@link net.bioclipse.lis.daos.UserDAO#getAll()}.
	 */
	@Test
	public void testGetAll() {
		
		User user1 = User.createUser("Getall Tester1");
		User user2 = User.createUser("Getall Tester2");
		getDAO().save(user1);
		getDAO().save(user2);
		
		session.flush();
		session.clear();
		
		List list = getDAO().findAll();
		assertTrue(list.contains(user1));
		assertTrue(list.contains(user2));
	}

	
	/**
	 * Test method for {@link net.bioclipse.lis.daos.UserDAO#save(net.bioclipse.lis.pojos.User)}.
	 */
	@Test
	public void testSave() {
		User user = User.createUser("Save Tester");
		getDAO().save(user);
		
		session.flush();
		session.clear();
		
		User savedUser = getDAO().getById(user.getId());
		assertEquals(user, savedUser);
		assertNotSame(user, savedUser);
	}
	
	/**
	 * Test method for {@link net.bioclipse.lis.daos.UserDAO#getById(long)}.
	 */
	@Test
	public void testGetById() {
		User user = User.createUser("Getbyid Tester");
		getDAO().save(user);
		
		session.flush();
		session.clear();
		
		User savedUser = getDAO().getById(new Long(user.getId()));
		assertEquals(user, savedUser);
		assertNotSame(user, savedUser);		
	}
	
	@Test
	public void testFindByName() {
		User user = User.createUser("findMe");
		getDAO().save(user);
		
		session.flush();
		session.clear();
		
		ArrayList<User> retrievedUsers = (ArrayList<User>)getDAO().findByName("findMe");
		User savedUser = retrievedUsers.get(0);
		assertEquals(user, savedUser);
		assertNotSame(user, savedUser);	
	}
}

public abstract class AbstractGenericDAOTest {

	protected IGenericDAO dao;
	protected Session     session;
	protected ApplicationContext context;
//snip
public AbstractGenericDAOTest(String DAOBeanName){
		context = new ClassPathXmlApplicationContext("applicationContext.xml");		
		dao = (IGenericDAO)context.getBean(DAOBeanName);
		session = SessionFactoryUtils.getSession(dao.getSessionFactory(),true);
		
	}

@Before
	public void setUp() throws Exception {

		net.bioclipse.lis.tests.Tools.newCleanDatabase();
		TransactionSynchronizationManager.bindResource(dao.getSessionFactory(), new SessionHolder(session));

//snipp

@After
	public void tearDown(){
		
		TransactionSynchronizationManager.unbindResource(dao.getSessionFactory());
		SessionFactoryUtils.releaseSession(session, dao.getSessionFactory());

And they works fine except for when I run alot of them at the same time...

[Marten Deinum]

Spring provides test classes for well everything you did on your own. The Spring test classes will also inject dependencies in your testclass! Also it will only load the applicationcontext once instead of before every test method, it also takes care of transaction management for you, instead of doing it yourself.

Read chapter 8 of the reference guide, which covers testing. You also might want to checkout the [url=http://www.springframework.org/docs/api/org/springframework/test/AbstractSpringContextTests.html]javadocs[url] regarding the test classes.

The rewrite in your case would be

public abstract class AbstractGenericDAOTest extends org.springframework.test.AbstractTransactionalSpringContextTests{

  private static final String[] LOCATIONS = {"applicationContext.xml"}

  public AbstractGenericDAOTest() {
    setAutowireMode(AUTOWIRE_BY_NAME);
  }

  protected String[] getConfigLocations() {
    return LOCATIONS;
  }
}

package net.bioclipse.lis.tests.daos;

import java.util.ArrayList;
import java.util.List;

import org.junit.Test;

import static org.junit.Assert.*;

import net.bioclipse.lis.genericDAO.IUserDAO;
import net.bioclipse.lis.pojos.User;

/**
 * Tests all the functionality of the <code>UserDAO</code>
 * 
 * @author jonathan
 *
 */
public class UserDAOTest extends AbstractGenericDAOTest {
	
	private GenericDao dao;
	
	//Spring will inject this for you.
	public void setIUserDao(GenericDao dao){
		return this.dao=dao;
	}
	
	public UserDAOTest() {
		super();
	}

	/**
	 * Test method for {@link net.bioclipse.lis.daos.UserDAO#delete(long)}.
	 */
	@Test
	public void testDelete() {
		User user   = User.createUser("Delete Tester");
		assertFalse(user.isDeleted());
		dao.save(user);
        setComplete()
        endTransaction();
        startTransaction();		
		
		dao.delete(user.getId());
		
        setComplete()
        endTransaction();
        startTransaction();		
		
		User deleted = dao.getById(new Long(user.getId()));
		assertTrue(deleted.isDeleted());
	}

	/**
	 * Test method for {@link net.bioclipse.lis.daos.UserDAO#getAll()}.
	 */
	@Test
	public void testGetAll() {
		
		User user1 = User.createUser("Getall Tester1");
		User user2 = User.createUser("Getall Tester2");
		dao.save(user1);
		dao.save(user2);
        setComplete()		
        endTransaction();
        startTransaction();		
		
		List list = dao.findAll();
		assertTrue(list.contains(user1));
		assertTrue(list.contains(user2));
	}

	
	/**
	 * Test method for {@link net.bioclipse.lis.daos.UserDAO#save(net.bioclipse.lis.pojos.User)}.
	 */
	@Test
	public void testSave() {
		User user = User.createUser("Save Tester");
		dao.save(user);
	        setComplete()	
        endTransaction();
        startTransaction();		
		
		User savedUser = dao.getById(user.getId());
		assertEquals(user, savedUser);
		assertNotSame(user, savedUser);
	}
	
	/**
	 * Test method for {@link net.bioclipse.lis.daos.UserDAO#getById(long)}.
	 */
	@Test
	public void testGetById() {
		User user = User.createUser("Getbyid Tester");
		dao.save(user);
	        setComplete()	
        endTransaction();
        startTransaction();		
		
		User savedUser = dao.getById(new Long(user.getId()));
		assertEquals(user, savedUser);
		assertNotSame(user, savedUser);		
	}
	
	@Test
	public void testFindByName() {
		User user = User.createUser("findMe");
		dao.save(user);
	        setComplete()	
        endTransaction();
        startTransaction();		
		
		ArrayList<User> retrievedUsers = (ArrayList<User>)dao.findByName("findMe");
		User savedUser = retrievedUsers.get(0);
		assertEquals(user, savedUser);
		assertNotSame(user, savedUser);	
	}
}

[Jonathan Alvarsson]

Thanks I'll have to test that and see if it solves my problems

// Jonathan

[Marten Deinum]

Your welcome, I give no garantues as I simply typed it in the edit box . Hmm I wonder is knowing the Spring API from the top of your head bad?!

[al0]

Thanks I'll have to test that and see if it solves my problems

// Jonathan

There is one small issue - Spring test classes are JUnit 3.8.1 based and you have strived to use JUnit 4.x. If using of Junit 4 is important for you, then start not from using Spring test classes, but just by converting application context in your tests into the static field. It should be enough to solve your problem.

BTW, I vaguely remember that some project exists for porting Spring test classes to JUnit4, but I do not remeber details. Try to search this forum, it was discussed here some time ago.

[Marten Deinum]

Oops, missed that bit .

Spring 2.1 provides JUnit 4 integration. However the lack of integration support for JUnit and/or TestNG led us to unitils. Next to that it also provides DBUnit integration and some other convenience tools.

[Jonathan Alvarsson]

//Spring will inject this for you.
public void setIUserDao(GenericDao dao){
return this.dao=dao;
}

Based upon what can Spring make this sort of injection? There is not any xml definitions to work by...

I need something like this:

        <bean id="userDAO" parent="abstractDAO">
        <property name="proxyInterfaces">
        	<value>net.bioclipse.lis.genericDAO.IUserDAO</value>
    	</property>
    	<property name="target">
        	<bean parent="abstractDAOTarget">
            	<constructor-arg>
                	<value>net.bioclipse.lis.pojos.User</value>
            	</constructor-arg>
        	</bean>
    	</property>
	</bean>

See: <http://www.ibm.com/developerworks/java/library/j-genericdao.html>

[al0]

Oops, missed that bit .

Spring 2.1 provides JUnit 4 integration. However the lack of integration support for JUnit and/or TestNG led us to unitils. Next to that it also provides DBUnit integration and some other convenience tools.

Spring 2.1 is not yet here (it even not reached RC stage).
And my first impression of unutils was not that good, but I have not used them, just have taken a look.

Really, I'm happy with JUnit 3.8.1 and do not see (for me) any real need in the migration to JUnit 4 or TestNG.