Ugly Sample of JDBC Promises in Play (probably with anti-patterns)

MyController.java

public void sendTextMessage() throws SQLException {

	// Open a connection
	CustomConnectionMgr.openConnection();
	
	// Tell the connection object to start a transaction
	CustomConnectionMgr.startTransaction();

	F.Promise<Integer> notifyBatchIdPromise;
	F.Promise<Integer> notifyConversationIdPromise;

	// Excecute a JDBC statement, which returns a Promise
	notifyBatchIdPromise = notifyBatchDao.insert();

	// Excecute another JDBC statement, which should be executed after notifyBatchDao.insert()
	notifyConversationIdPromise = notifyBatchIdPromise.flatMap( notifyBatchId -> {
	   return notifyConversationDao.insert(notifyBatchId);
	});

	// Handle failure for first query
	notifyBatchIdPromise.onFailure(exception -> {
	   throw new Exception( exception )   
	   CustomConnectionMgr.closeConnection();
	});

	// Handle failure for second query
	notifyConversationIdPromise.onFailure(exception -> {
	   CustomConnectionMgr.closeConnection();
	});

	CustomConnectionMgr.endTransaction();
	CustomConnectionMgr.closeConnection();
}