I came across some JMS calling code that initializes the JMS session inside of its constructor. The calling code implements the ExceptionListener interface and passes a reference to this to the connection factory object, as shown below:
public class JmsCode implements ExceptionListener {
private static final Logger logger = LoggerFactory.getLogger(JmsCode.class);
public JmsCode(String url, String username, String password, String trustStorePath, char[] trustStorePassword) throws JMSException {
ActiveMQSslConnectionFactory connectionFactory = new ActiveMQSslConnectionFactory(url);
connectionFactory.setUserName(username);
connectionFactory.setPassword(password);
connectionFactory.setTrustStore(trustStorePath);
connectionFactory.setTrustStorePassword(new String(trustStorePassword));
connectionFactory.setExceptionListener(this);
Connection connection = connectionFactory.createConnection();
connection.start();
Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
}
@Override
public void onException(JMSException e) {
logger.error("Unexpected JMS exception caught", e);
}
}
I am wondering if it is safe to pass a reference to this from the JmsCode constructor given that the object hasn't been fully constructed yet. I came across a similar question which had me reading up on IBM's article on not publishing this during construction. While I agree with their reasoning, I am not sure if it applies in this case since the only thing the exception listener is doing is logging via a static and final member. Is the code above safe (ignoring someone else being tempted to change the exception listener method to use some instance state of the object)?