DataSource valid connection but getURL returns null?

Question

I had this situation reported to me with Informix over Payara (Glassfish).

Is there any cases where we could get a valid connection but DatabaseMetaData getURL could return null?

Answer 1

If you create an Informix JDBC connection from a DataSource, then from the driver's perspective there is no URL, and DatabaseMetaData.getURL() will return null.

If you make a connection using DriverManager and pass in a URL, then you should get that URL back from the metadata.

One could argue that the connection could 'build' a URL from the DataSource to give back to you, but the Informix JDBC driver today does not do that.

Answer 2

Returning null from DatabaseMetaData.getURL() is allowed, as stated in the Javadoc:

Returns: the URL for this DBMS or null if it cannot be generated

The DatabaseMetaData.getURL() method is primarily intended for informational purposes, so you shouldn't rely on its result in any way.

Probably the Informix driver has no way to obtain the original URL used for the connection and simply returns null in its implementation of DatabaseMetaData.getURL() .