Improve error for incorrect class for xa-datasource-class, etc. --------------------------------------------------------------- Key: WFLY-14436 URL: https://issues.redhat.com/browse/WFLY-14436 Project: WildFly Issue Type: Enhancement Components: Server Reporter: Sudeshna Sur Assignee: Sudeshna Sur Priority: Minor If a driver class (a class implementing {{java.sql.Driver}}) is specified as an {{xa-datasource-class}} in a {{driver}} configuration (in {{[standalone*/domain].xml}}), a generic error is reported: {noformat} ... ERROR [org.jboss.as.controller.management-operation] (ServerService Thread Pool -- 43) WFLYCTL0013: Operation ("add") failed - address: ([ ("subsystem" => "datasources"), ("jdbc-driver" => "oracle") ]) - failure description: "WFLYJCA0114: Failed to load datasource class: oracle.jdbc.OracleDriver" {noformat} A similar sort of (generic) failure will arise if a driver class is specified as a {{<datasource-class>}} (though it is not typical to specify a non-XA datasource class). It would be more helpful to provide something descriptive indicating that the class cannot be cast to {{javax.sql.XADataSource}} which is the underlying reason for the failure - {{OracleDriver}} implements the {{java.sql.Driver}} interface instead of {{javax.sql.XADataSource}} or {{javax.sql.DataSource}}. There is a class cast exception raised at a low level - as captured by a Byteman rule (for exception exit from org.jboss.as.connector.subsystems.datasources.JdbcDriverAdd) - and we should know the type to which cast is attempted in the context of the code below. {noformat} ... [BMAN] WFLYJCA0114: Failed to load datasource class: oracle.jdbc.OracleDriver ... org.jboss.as.controller.OperationFailedException: WFLYJCA0114: Failed to load datasource class: oracle.jdbc.OracleDriver [ "WFLYJCA0114: Failed to load datasource class: oracle.jdbc.OracleDriver" ] ... at org.jboss.as.connector.subsystems.datasources.JdbcDriverAdd.performRuntime(JdbcDriverAdd.java:128) ... at org.jboss.as.controller.AbstractAddStepHandler.performRuntime(AbstractAddStepHandler.java:338) ... at org.jboss.as.controller.AbstractAddStepHandler$1.execute(AbstractAddStepHandler.java:159) ... at org.jboss.as.controller.AbstractOperationContext.executeStep(AbstractOperationContext.java:999) ... at org.jboss.as.controller.AbstractOperationContext.processStages(AbstractOperationContext.java:743) ... at org.jboss.as.controller.AbstractOperationContext.executeOperation(AbstractOperationContext.java:467) ... at org.jboss.as.controller.ParallelBootOperationStepHandler$ParallelBootTask.run(ParallelBootOperationStepHandler.java:384) ... at org.jboss.threads.ContextClassLoaderSavingRunnable.run(ContextClassLoaderSavingRunnable.java:35) ... at org.jboss.threads.EnhancedQueueExecutor.safeRun(EnhancedQueueExecutor.java:1982) ... at org.jboss.threads.EnhancedQueueExecutor$ThreadBody.doRunTask(EnhancedQueueExecutor.java:1486) ... at org.jboss.threads.EnhancedQueueExecutor$ThreadBody.run(EnhancedQueueExecutor.java:1348) ... at java.lang.Thread.run(Thread.java:748) ... at org.jboss.threads.JBossThread.run(JBossThread.java:485) ... Caused by: java.lang.ClassCastException: class oracle.jdbc.OracleDriver ... at java.lang.Class.asSubclass(Class.java:3404) ... at org.jboss.as.connector.subsystems.datasources.JdbcDriverAdd.performRuntime(JdbcDriverAdd.java:126) {noformat} This type of misconfiguration (specifying a driver class as an {{xa-datasource-class}}) could go undetected prior to 7.2 as there was no attempt to instantiate the class (e.g. the {{xa-datasource-class}}) unless a pool of the relevant type (an {{xa-datasource}} pool) was declared. The resolution is to specify an Oracle implementation class that implements the relevant interface (usually {{javax.sql.XADataSource}}) or to remove the {{xa-datasource-class}} (e.g. if no {{xa-datasource}} pool is to be used) or {{datasource-class}} (for non-XA pools neither a driver nor datasource class implementation is usually needed for JDBC 4 compliant implementations). To reproduce, configuration like the below can be used in {{standalone*.xml}}: {code:xml} <datasource jndi-name="java:jboss/datasources/oracle" pool-name="Oracle" enabled="true" jta="true"> ... <driver>oracle</driver> <security> ... </security> </datasource> ... <drivers> <driver name="oracle" module="com.oracle"> <xa-datasource-class>oracle.jdbc.OracleDriver</xa-datasource-class> </driver> ... </drivers> {code}