In WildFly 21.0.0, tried to create a simple Oracle XA datasource.

At step 3 (JDBC Driver), there is an optional field for "Driver Class Name" and the default supplied is "oracle.jdbc.driver.OracleDriver"

A driver class (i.e. an implementation of java.sql.Driver) cannot be used with an XA DataSource.

• Instead an implementation of javax.sql.XADataSource must be supplied.
• An XA DataSource class is required (it is mandatory not optional).
• Even if the field retained the class (it doesn't - see below), it is confusing to call it a "Driver Class Name" as a "Driver Class" is distinctly different from an "XADataSource Class" (these are different Java interfaces). The two types cannot be used interchangeably.

Users should be prompted to provide an appropriate class for their specific driver (e.g. oracle.jdbc.xa.client.OracleXADataSource). Supplying a default is not a good idea as it may change with driver releases.

I tried to substitute the XA class in the "Driver Class Name" field but the required configuration is missing (looks like the field is ignored). The required configuration needs to appear as below (with the provided class):

                    <xa-datasource-class>SUPPLIED_CLASS_HERE</xa-datasource-class>

Note that I'm not creating a module (which might work differently), I'm selecting the Oracle JDBC driver jar file (which I pre-copied to the WildFly standalone/deployments directory) from the drop down and I'm removing the module name as module deployments are a bit more complex than needed in most cases.