I get the following when using the 11g JDBC driver (ojdbc6.jar) when the OracleDriver class is accessed multiple times within the same JVM

[dbunit] Aug 30, 2007 9:12:44 AM oracle.jdbc.driver.OracleDriver registerMBeans
[dbunit] SEVERE: Error while registering Oracle JDBC Diagnosability MBean.
[dbunit] javax.management.InstanceAlreadyExistsException: com.oracle.jdbc:type=diagnosability,name=java.net.URLClassLoader@14318bb
[dbunit] at com.sun.jmx.mbeanserver.Repository.addMBean(Repository.java:453)
[dbunit] at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.internal_addObject(DefaultMBeanServerInterceptor.java:1484)
[dbunit] at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerDynamicMBean(DefaultMBeanServerInterceptor.java:963)
[dbunit] at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerObject(DefaultMBeanServerInterceptor.java:917)
[dbunit] at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerMBean(DefaultMBeanServerInterceptor.java:312)
[dbunit] at com.sun.jmx.mbeanserver.JmxMBeanServer.registerMBean(JmxMBeanServer.java:482)
[dbunit] at oracle.jdbc.driver.OracleDriver.registerMBeans(OracleDriver.java:305)
[dbunit] at oracle.jdbc.driver.OracleDriver$1.run(OracleDriver.java:213)
[dbunit] at java.security.AccessController.doPrivileged(Native Method)
[dbunit] at oracle.jdbc.driver.OracleDriver.<clinit>(OracleDriver.java:209)
[dbunit] at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
[dbunit] at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
[dbunit] at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
[dbunit] at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
[dbunit] at java.lang.Class.newInstance0(Class.java:355)
[dbunit] at java.lang.Class.newInstance(Class.java:308)
[dbunit] at org.dbunit.ant.DbUnitTask.createConnection(DbUnitTask.java:340)
[dbunit] at org.dbunit.ant.DbUnitTask.execute(DbUnitTask.java:266)
[dbunit] at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:288)
[dbunit] at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)
[dbunit] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
[dbunit] at java.lang.reflect.Method.invoke(Method.java:597)
[dbunit] at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:105)
[dbunit] at org.apache.tools.ant.Task.perform(Task.java:348)
[dbunit] at org.apache.tools.ant.Target.execute(Target.java:357)
[dbunit] at org.apache.tools.ant.Target.performTasks(Target.java:385)
[dbunit] at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1329)
[dbunit] at org.apache.tools.ant.helper.SingleCheckExecutor.executeTargets(SingleCheckExecutor.java:38)
[dbunit] at org.apache.tools.ant.Project.executeTargets(Project.java:1181)
[dbunit] at org.apache.tools.ant.taskdefs.Ant.execute(Ant.java:416)
[dbunit] at org.apache.tools.ant.taskdefs.CallTarget.execute(CallTarget.java:105)
[dbunit] at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:288)
[dbunit] at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)
[dbunit] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
[dbunit] at java.lang.reflect.Method.invoke(Method.java:597)
[dbunit] at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:105)
[dbunit] at org.apache.tools.ant.Task.perform(Task.java:348)
[dbunit] at org.apache.tools.ant.Target.execute(Target.java:357)
[dbunit] at org.apache.tools.ant.Target.performTasks(Target.java:385)
[dbunit] at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1329)
[dbunit] at org.apache.tools.ant.Project.executeTarget(Project.java:1298)
[dbunit] at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:41)
[dbunit] at org.apache.tools.ant.Project.executeTargets(Project.java:1181)
[dbunit] at org.apache.tools.ant.Main.runBuild(Main.java:698)
[dbunit] at org.apache.tools.ant.Main.startAnt(Main.java:199)
[dbunit] at org.apache.tools.ant.launch.Launcher.run(Launcher.java:257)
[dbunit] at org.apache.tools.ant.launch.Launcher.main(Launcher.java:104)

In our case we're calling multiple DB operations within the same build file and then after the 1st call we encounter that error for every operation.

It doesn't fail anything but it would seem that there is a static block in the OracleDriver class that tries to register the MBean every time it is touched whether or not it was previously registered.

Might consider a flag or some check to prevent this every time as it made some people skittish when they encountered it, lol.

This looks to be a class loader issue. After playing around with this for a bit and looking to see how Ant's class loader behaves I think the following code snippet is indicative to the behviour

import java.net.URL;
import java.net.URLClassLoader;

public class OracleDriverTest {
public static void main(String[] args) throws Exception {
OracleDriverTest test = new OracleDriverTest();
test.test();
}

public void test() throws Exception {
String oracleJar = "/ojdbc6.jar";
String oracleDriverName = "oracle.jdbc.driver.OracleDriver";

for (int i = 0; i < 5; i++) {
MyClassLoader p = new MyClassLoader(new URL[]{this.getClass().getResource(oracleJar)}, this.getClass().getClassLoader());
Class driver = p.loadClass2(oracleDriverName);
System.out.println("Driver classloader is " + driver.getClassLoader());
driver.newInstance();
}
System.out.println("Thread classloader = " + Thread.currentThread().getContextClassLoader());
}

private class MyClassLoader extends URLClassLoader {
public MyClassLoader(URL[] urls, ClassLoader parent) {
super(urls, parent);
}

/**
* Load method to skip checking the parent class loader
*
* @param name
* @return
* @throws ClassNotFoundException
*/
public Class<?> loadClass2(String name) throws ClassNotFoundException {
return super.findClass(name);
}
}
}

Essentially, what this is simulating is the class loader behavior where the child classloader skips looking to the parent classloader when trying to resolve a class.

As you can see by my stellar sysouts the driver class is loaded by each individual class loader for each iteration.

However, the MBean registration looks to be using the Thread's class loader which is the same for each failure.

for the 5 iterations you will see the original exception displayed 4 times. The first time it registers w/o any issues and then subsequently fails.

I'm, by far, not a class loader expert so I don't know which side of the fence this undesired behavior falls (Ant or Oracle). I originally logged posted here since this was new behavior since we upgraded to the 11g drivers.

I´m having the same problem using JBOSS + hibernate

Herrera

I am having the same problem with Oracle 10g Express edition + Eclipse 3.3, Tomcat 6.0:

SEVERE: Error while registering Oracle JDBC Diagnosability MBean.
javax.management.MalformedObjectNameException: Invalid character '
' in value part of property
at javax.management.ObjectName.construct(ObjectName.java:602)
at javax.management.ObjectName.<init>(ObjectName.java:1394)
at oracle.jdbc.driver.OracleDriver.registerMBeans(OracleDriver.java:303)
at oracle.jdbc.driver.OracleDriver$1.run(OracleDriver.java:213)
at java.security.AccessController.doPrivileged(Native Method)
at oracle.jdbc.driver.OracleDriver.<clinit>(OracleDriver.java:209)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:169)
at org.example.ch03.Database.lookupFullname(Database.java:24)
at org.example.ch03.HelloServlet.doGet(HelloServlet.java:38)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:690)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:263)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:584)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
at java.lang.Thread.run(Thread.java:619)

This seems to fix my issues I was having with ant. Am I to assume that this is a very isolated patch and doesn't contain any other changes?

I was getting "SEVERE: Error while registering Oracle JDBC Diagnosability MBean". I was using the patched jar though. I switched to an older driver and the problem went away.

Message was edited by:
dangerismymiddlename.com

Hi!

I just saw, that there is already a patch on OTN. But I cannot find it on OTN - tried to look in the list of "new downloads" (http://www.oracle.com/technology/software/new_downloads.html) - but there is no updated JDBC driver?! Even in other categories I did not find any 11g JDBC driver as a seperate package.