Question

Connection.close() may throw SqlException, but I have always assumed that it is safe to ignore any such exceptions (and I have never seen code that does not ignore them).

Normally I would write:

 try{     connection.close();  }catch(Exception e) {} 

Or

 try{     connection.close();  }catch(Exception e) {      logger.log(e.getMessage(), e);   } 

The question is:

1. Is it bad practice (and has anyone had problems when ignoring such exceptions).
2. When Connection.close() does throw any exception.
3. If it is bad how should I handle the exception.

Comment:

I know that discarding exceptions is evil, but I’m reffering only to exceptions thrown when closing a connection (and as I’ve seen this is fairly common in this case).

Does anyone know when Connection.close() may throw anything?

Answer 1

Actually, what you’re doing is (almost) best practice 🙂 here’s what I saw in Spring’s JdbcUtils.java. So, you might want to add another Catch block.

/**  * Close the given  ResultSet and ignore any thrown exception.  * This is useful for typical finally blocks in manual  code.  * @param resultSet the  ResultSet to close  * @see javax.resource.cci.ResultSet#close()  */ private void closeResultSet(ResultSet resultSet) {   if (resultSet != null) {     try {       resultSet.close();     }     catch (SQLException ex) {       logger.debug('Could not close  ResultSet', ex);     }     catch (Throwable ex) {       // We don't trust the  driver: It might throw RuntimeException or Error.       logger.debug('Unexpected exception on closing  ResultSet', ex);     }   } }