I've recently had to look into connecting to an Oracle 9i instance using the latest version of SQLDeveloper (20 as of the time of this writing). Unfortunately trying to connect to the 9i database resulted in SQLDeveloper failing the connection test - "Status : Failure -Test failed: java.lang.ArrayIndexOutOfBoundsException".


This didn't look like a common database connectivity error so it was time to start looking at JDBC drivers. The About dialog box showed the path to the JDBC driver used under the jdbc.library property. I first wanted to check with version of JDBC drivers were used, so checked it via the Command Prompt. It looked like 19c drivers were in use.





I downloaded the 12c drivers from Oracle to try first, thinking that a version lower would be OK. The jdbc8.jar file in SQLDeveloper was then replaced with the 12c driver and I ran the version check again...


The 12c drivers were in place so I opened up SQLDeveloper again and tried to connect to the 9i instance. Unfortunately this failed with "Status : Failure -Test failed: oracle.jdbc.driver.OracleDriverExtension.getConnection(Ljava/lang/String;Ljava/util/Properties;)Ljava/sql/Connection;" but I decided to exit SQLDeveloper and open it again, then the connection worked...


I also made sure that I was connected to the 9i instance with some SQL...


At this point I decided to revert the changes (replacing 12c with 19c drivers). For some reason, the "OracleDriverExtension.getConnection" error came up, instead of the error I was expecting. This confirmed my suspicion that there's some sort of caching going on with SQLDeveloper, so it seems necessary to open/close it a couple of times after changing drivers.

This workaround lets you connect to an old Oracle 9i instance, and of course any new 19c features are going to be lost if you're connecting to more recent versions of the database.

-i