DbUnitHelper.java

package util;

import java.io.FileInputStream;

import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;

import org.dbunit.IDatabaseTester;
import org.dbunit.JdbcDatabaseTester;
import org.dbunit.dataset.IDataSet;
import org.dbunit.dataset.xml.FlatXmlDataSetBuilder;

public class DbUnitHelper {

	private String driver;
	private String url;
	private String user;
	private String password;

	public DbUnitHelper(EntityManager manager) {
		EntityManagerFactory factory = manager.getEntityManagerFactory();
		driver = (String) factory.getProperties().get("hibernate.connection.driver_class");
		url = (String) factory.getProperties().get("hibernate.connection.url");
		user = (String) factory.getProperties().get("hibernate.connection.user");
		password = (String) factory.getProperties().get("hibernate.connection.password");
	}
	
	public void insert(String dbUnitXmlPath) {

		try {
			
			IDatabaseTester dbTester = new JdbcDatabaseTester(driver, url, user, password);
			IDataSet dataSet = new FlatXmlDataSetBuilder().build(new FileInputStream(dbUnitXmlPath));
			
			dbTester.setDataSet(dataSet);
			dbTester.onSetup();
 
		} catch (Exception e) {
			e.printStackTrace();
			throw new RuntimeException(e);
		}
	}
}

DbUnitHelperSpec.java

package util;

import static org.junit.Assert.assertEquals;

import javax.persistence.EntityManager;
import javax.persistence.Persistence;

import org.junit.Test;

import domain.ValueStream;

public class DbUnitHelperSpec {
	
	@Test
	public void shouldLoadDataForTestingGivenEntityManager() {
		
		EntityManager manager = Persistence.createEntityManagerFactory("default").createEntityManager();
		new DbUnitHelper(manager).insert("test/"+this.getClass().getSimpleName() + ".xml");
		
		//this is the test entity
		ValueStream vs = manager.find(ValueStream.class, 1L);
		assertEquals("Test", vs.getTeamName());
	}

}