X-Git-Url: http://wamblee.org/gitweb/?a=blobdiff_plain;ds=sidebyside;f=test%2Fenterprise%2Fsrc%2Fmain%2Fjava%2Forg%2Fwamblee%2Fsupport%2Fpersistence%2FJpaBuilder.java;fp=test%2Fenterprise%2Fsrc%2Fmain%2Fjava%2Forg%2Fwamblee%2Fsupport%2Fpersistence%2FJpaBuilder.java;h=8b6e339935f01206ee3f795e16a8df4be49beeed;hb=2207a1e695ce23e79678c232cff2ceb84ebaa801;hp=0000000000000000000000000000000000000000;hpb=4985b85f86028eb896ac853134cb66a1299815a5;p=utils

diff --git a/test/enterprise/src/main/java/org/wamblee/support/persistence/JpaBuilder.java b/test/enterprise/src/main/java/org/wamblee/support/persistence/JpaBuilder.java
new file mode 100644
index 00000000..8b6e3399
--- /dev/null
+++ b/test/enterprise/src/main/java/org/wamblee/support/persistence/JpaBuilder.java
@@ -0,0 +1,136 @@
+package org.wamblee.support.persistence;
+
+import java.util.Map;
+import java.util.TreeMap;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import javax.naming.InitialContext;
+import javax.naming.NamingException;
+import javax.persistence.EntityManager;
+import javax.persistence.EntityManagerFactory;
+import javax.persistence.EntityTransaction;
+import javax.persistence.Persistence;
+import javax.sql.DataSource;
+
+import org.wamblee.support.jndi.StubInitialContextFactory;
+
+
+/**
+ * Utility for building an appropriately configured EntityManagerFactory. The
+ * idea is that a persistence.xml is used unchanged from the production version.
+ * This utility will then add the additional properties required for execution
+ * in a standalone environment.
+ * 
+ * The other purpose is to to shield dependencies of the test code on a
+ * particular JPA provider.
+ */
+public class JpaBuilder {
+
+	private static final Logger LOGGER = Logger.getLogger(JpaBuilder.class
+			.getName());
+
+	/**
+	 * Callback interface to execute some JPA code within a transaction with the
+	 * entitymanager to use provided as input.
+	 */
+	public static interface JpaUnitOfWork<T> {
+		/**
+		 * Executes the unit of work. A transaction has been started.  
+		 * @param em Entity manager. 
+		 * @return Result of the execute method. If you don't want to return anything use
+		 *  <code>Void</code> for the return type and return null from the implementation. 
+		 */
+		T execute(EntityManager em);
+	}
+
+	private PersistenceUnitDescription persistenceUnit;
+	private DataSource dataSource;
+	private EntityManagerFactory factory;
+
+	/**
+	 * Constructs the builder.
+	 * 
+	 * @param aDataSource
+	 *            Datasource of database.
+	 * @param aPersistenceUnit
+	 *            Persistence unit.
+	 */
+	public JpaBuilder(DataSource aDataSource,
+			PersistenceUnitDescription aPersistenceUnit) {
+		persistenceUnit = aPersistenceUnit;
+		dataSource = aDataSource;
+		StubInitialContextFactory.register();
+	}
+
+	/**
+	 * Starts the builder, which in particular, mocks JNDI, binds the datasource
+	 * the JNDI where the persistence unit expects it, creates the entity
+	 * manager factory, and forces creation of the database schema.
+	 */
+	public void start() throws Exception {
+		try {
+			InitialContext ctx = new InitialContext();
+			ctx.bind(persistenceUnit.getJndiName(), dataSource);
+		} catch (NamingException e) {
+			throw new RuntimeException("JNDI problem", e);
+		}
+		factory = createFactory();
+		execute(new JpaUnitOfWork<Void>() {
+			public Void execute(EntityManager em) {
+				// Empty, just to trigger database schema creation.
+				return null;
+			}
+		});
+	}
+
+	/**
+	 * Stops the entity manager factory and disables JNDI mocking. 
+	 */
+	public void stop() {
+		StubInitialContextFactory.unregister();
+		factory.close();
+	}
+
+	/**
+	 * Creates a new entity manager factory. Typically not used by test code. 
+	 * @return Entity manager factory. 
+	 */
+	public EntityManagerFactory createFactory() {
+		Map<String, String> jpaProps = new TreeMap<String, String>();
+	
+		JpaCustomizerBuilder.getCustomizer().customize(persistenceUnit, jpaProps);
+		
+		//jpaProps.put("javax.persistence.provider", HibernatePersistence.class.getName());
+		EntityManagerFactory factory = Persistence.createEntityManagerFactory(persistenceUnit
+				.getUnitName(), jpaProps);
+		
+		LOGGER.info("Using " + factory.getClass());
+		return factory;
+	}
+
+	/**
+	 * Executes a unit of work. This creates an entitymanager and runs the 
+	 * {@link JpaUnitOfWork#execute(EntityManager)} within a transaction, passing
+	 * it the entity manager. Use of this method saves a lot of typing for applications. 
+	 * 
+	 * @param aWork Work to execute. 
+	 * @return The return value of the execute method of the unit of work. 
+	 */
+	public <T> T execute(JpaUnitOfWork<T> aWork) throws Exception {
+		EntityManager em = factory.createEntityManager();
+		EntityTransaction transaction = em.getTransaction();
+		transaction.begin();
+		try {
+			T value = aWork.execute(em);
+			transaction.commit();
+			return value; 
+		} catch (Exception e) {
+			LOGGER.log(Level.WARNING, "Exception occured", e);
+			transaction.rollback();
+			throw e; 
+		} finally {
+			em.close();
+		}
+	}
+}