Catch a root cause exception under a Java IO Exception

[Prasanna krishnan]

Hi All,

I have some java code which initialises a MBean server connection. This code is called by a ant task. The ant task uses parameters like host name, username and password. On executing the ant task with the parameters, I get an exception as shown below:

/**
* This is the standard ant entry point for task
* execution.
* @throws BuildException
*/
public void execute() throws BuildException
{

try
{
checkRequiredParameters();
if (mSetAntClassLoader)
{
mTaskClassLoader =
(AntClassLoader)this.getClass().getClassLoader();
mTaskClassLoader.setThreadContextLoader();
}
initConnection(mHostname, mPortString, mUsername, mPassword);

//verify MDSDOmainRuntimeMBean is registered.
boolean registered =
mConnection.isRegistered(getMDSDomainRuntimeMBeanObjectName());


if (registered)
{
log("MDSDomainRuntimeMBean registered.", Project.MSG_INFO);
validatePartition();
}
else
{
throw new BuildException("MDSDomainRuntimeMBean is not registered. MDS infrastructure is not available.");

}

if (isAttributeSet(mApplication) && isAttributeSet(mServer))
{
//verify MDSAppRuntimeMBean is registered.
boolean appRegistered =
mConnection.isRegistered(getAppRuntimeMBeanName());
if (!appRegistered)
{
throw new BuildException("MDSAppRuntimeMBean is not registered. MDS may not be available for application " +
mApplication + " on server " +
mServer);
}
else
{
log("MDSAppRuntimeMBean registered.", Project.MSG_INFO);
validateMetadataLabel();
}
}
if (mSetAntClassLoader && mTaskClassLoader != null)
{
mTaskClassLoader.resetThreadContextLoader();
}

System.out.println("MDS validated successfully.");
}
catch (BuildException be)
{
throw be;
}
catch (Exception e)
{
e.printStackTrace();
throw new BuildException(e);
}
finally
{
if (mConnector != null)
{
try
{
mConnector.close();
}
catch (Exception e)
{
throw new BuildException(e);
}
}
}
}


EXCEPTION
------------------

validateMDSwithInvalidHost:
[ValidateMDS] java.io.IOException
[ValidateMDS] at weblogic.management.remote.common.ClientProviderBase.makeConnection(ClientProviderBase.java:187)
[ValidateMDS] at weblogic.management.remote.common.ClientProviderBase.newJMXConnector(ClientProviderBase.java:81)
[ValidateMDS] at javax.management.remote.JMXConnectorFactory.newJMXConnector(JMXConnectorFactory.java:338)
[ValidateMDS] at javax.management.remote.JMXConnectorFactory.connect(JMXConnectorFactory.java:247)
[ValidateMDS] at oracle.apps.fnd.provisioning.ant.taskdefs.validation.ValidateMDS.initConnection(ValidateMDS.java:352)
[ValidateMDS] at oracle.apps.fnd.provisioning.ant.taskdefs.validation.ValidateMDS.execute(ValidateMDS.java:207)
[ValidateMDS] at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:288)
[ValidateMDS] at sun.reflect.GeneratedMethodAccessor2.invoke(Unknown Source)
[ValidateMDS] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
[ValidateMDS] at java.lang.reflect.Method.invoke(Method.java:597)
[ValidateMDS] at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:105)
[ValidateMDS] at org.apache.tools.ant.Task.perform(Task.java:348)
[ValidateMDS] at org.apache.tools.ant.Target.execute(Target.java:357)
[ValidateMDS] at org.apache.tools.ant.Target.performTasks(Target.java:385)
[ValidateMDS] at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1329)
[ValidateMDS] at org.apache.tools.ant.Project.executeTarget(Project.java:1298)
[ValidateMDS] at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:41)
[ValidateMDS] at org.apache.tools.ant.Project.executeTargets(Project.java:1181)
[ValidateMDS] at org.apache.tools.ant.Main.runBuild(Main.java:698)
[ValidateMDS] at org.apache.tools.ant.Main.startAnt(Main.java:199)
[ValidateMDS] at org.apache.tools.ant.launch.Launcher.run(Launcher.java:257)
[ValidateMDS] at org.apache.tools.ant.launch.Launcher.main(Launcher.java:104)
[ValidateMDS] Caused by: javax.naming.ServiceUnavailableException [Root exception is java.net.UnknownHostException: stpcy05]
[ValidateMDS] at weblogic.jndi.internal.ExceptionTranslator.toNamingException(ExceptionTranslator.java:34)
[ValidateMDS] at weblogic.jndi.WLInitialContextFactoryDelegate.toNamingException(WLInitialContextFactoryDelegate.java:783)
[ValidateMDS] at weblogic.jndi.WLInitialContextFactoryDelegate.getInitialContext(WLInitialContextFactoryDelegate.java:365)
[ValidateMDS] at weblogic.jndi.Environment.getContext(Environment.java:315)
[ValidateMDS] at weblogic.jndi.Environment.getContext(Environment.java:285)
[ValidateMDS] at weblogic.jndi.WLInitialContextFactory.getInitialContext(WLInitialContextFactory.java:117)
[ValidateMDS] at javax.naming.spi.NamingManager.getInitialContext(NamingManager.java:667)
[ValidateMDS] at javax.naming.InitialContext.getDefaultInitCtx(InitialContext.java:288)
[ValidateMDS] at javax.naming.InitialContext.init(InitialContext.java:223)
[ValidateMDS] at javax.naming.InitialContext.<init>(InitialContext.java:197)
[ValidateMDS] at weblogic.management.remote.common.ClientProviderBase.makeConnection(ClientProviderBase.java:169)
[ValidateMDS] ... 21 more
[ValidateMDS] Caused by: java.net.UnknownHostException: stpcy05
[ValidateMDS] at java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method)
[ValidateMDS] at java.net.InetAddress$1.lookupAllHostAddr(InetAddress.java:849)
[ValidateMDS] at java.net.InetAddress.getAddressFromNameService(InetAddress.java:1200)
[ValidateMDS] at java.net.InetAddress.getAllByName0(InetAddress.java:1153)
[ValidateMDS] at java.net.InetAddress.getAllByName(InetAddress.java:1083)
[ValidateMDS] at java.net.InetAddress.getAllByName(InetAddress.java:1019)
[ValidateMDS] at weblogic.rjvm.RJVMFinder.getDnsEntries(RJVMFinder.java:422)
[ValidateMDS] at weblogic.rjvm.RJVMFinder.findOrCreateInternal(RJVMFinder.java:192)
[ValidateMDS] at weblogic.rjvm.RJVMFinder.findOrCreate(RJVMFinder.java:170)
[ValidateMDS] at weblogic.rjvm.ServerURL.findOrCreateRJVM(ServerURL.java:153)
[ValidateMDS] at weblogic.jndi.WLInitialContextFactoryDelegate$1.run(WLInitialContextFactoryDelegate.java:344)
[ValidateMDS] at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:363)
[ValidateMDS] at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:147)
[ValidateMDS] at weblogic.jndi.WLInitialContextFactoryDelegate.getInitialContext(WLInitialContextFactoryDelegate.java:339)
[ValidateMDS] ... 29 more




My question is: how can we catch the UnknownHostException here?
Please let me know.
Thanks

[Rob Spoor]

Please Use Code Tags.

[Prasanna krishnan]

Prasanna krishnan wrote:Hi All,

I have some java code which initialises a MBean server connection. This code is called by a ant task. The ant task uses parameters like host name, username and password. On executing the ant task with the parameters, I get an exception as shown below:

  /**
     * This is the standard ant entry point for task
     * execution.
     * @throws BuildException
     */
    public void execute() throws BuildException
    {

        try
        {
            checkRequiredParameters();
            if (mSetAntClassLoader)
            {
                mTaskClassLoader =
                        (AntClassLoader)this.getClass().getClassLoader();
                mTaskClassLoader.setThreadContextLoader();
            }
            initConnection(mHostname, mPortString, mUsername, mPassword);

            //verify MDSDOmainRuntimeMBean is registered.
            boolean registered =
                mConnection.isRegistered(getMDSDomainRuntimeMBeanObjectName());


            if (registered)
            {
                log("MDSDomainRuntimeMBean registered.", Project.MSG_INFO);
                validatePartition();
            }
            else
            {
                throw new BuildException("MDSDomainRuntimeMBean is not registered. MDS infrastructure is not available.");

            }

            if (isAttributeSet(mApplication) && isAttributeSet(mServer))
            {
                //verify MDSAppRuntimeMBean is registered.
                boolean appRegistered =
                    mConnection.isRegistered(getAppRuntimeMBeanName());
                if (!appRegistered)
                {
                    throw new BuildException("MDSAppRuntimeMBean is not registered. MDS may not be available for application " +
                                             mApplication + " on server " +
                                             mServer);
                }
                else
                {
                    log("MDSAppRuntimeMBean registered.", Project.MSG_INFO);
                    validateMetadataLabel();
                }
            }
            if (mSetAntClassLoader && mTaskClassLoader != null)
            {
                mTaskClassLoader.resetThreadContextLoader();
            }

            System.out.println("MDS validated successfully.");
        }
        catch (BuildException be)
        {
            throw be;
        }
        /*catch (UnknownHostException ue)
        {
            throw new BuildException("Invalid Host Name");
        }
        catch (SecurityException se)
        {
            throw new BuildException("Invalid UserName/Password");
        }*/
       /* catch (IOException ioe)
        {
            System.out.println("Got IO Exception");
            if (ioe.getRootCause() instanceof UnknownHostException)
            {
               System.out.println("Got the cause");
               throw new BuildException("Invalid adminHost Parameter");
            }


        }*/
        catch (Exception e)
        {
            if (e.getRootCause().getCause() instanceof UnknownHostException)
            {
               System.out.println("Got the cause");
               throw new BuildException("Invalid adminHost Parameter");
            }

          /*  e.printStackTrace();
            throw new BuildException(e);*/
        }
        finally
        {
            if (mConnector != null)
            {
                try
                {
                    mConnector.close();
                }
                catch (Exception e)
                {
                    throw new BuildException(e);
                }
            }
        }
    }

EXCEPTION
------------------

validateMDSwithInvalidHost:
[ValidateMDS] java.io.IOException
[ValidateMDS] at weblogic.management.remote.common.ClientProviderBase.makeConnection(ClientProviderBase.java:187)
[ValidateMDS] at weblogic.management.remote.common.ClientProviderBase.newJMXConnector(ClientProviderBase.java:81)
[ValidateMDS] at javax.management.remote.JMXConnectorFactory.newJMXConnector(JMXConnectorFactory.java:338)
[ValidateMDS] at javax.management.remote.JMXConnectorFactory.connect(JMXConnectorFactory.java:247)
[ValidateMDS] at oracle.apps.fnd.provisioning.ant.taskdefs.validation.ValidateMDS.initConnection(ValidateMDS.java:352)
[ValidateMDS] at oracle.apps.fnd.provisioning.ant.taskdefs.validation.ValidateMDS.execute(ValidateMDS.java:207)
[ValidateMDS] at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:288)
[ValidateMDS] at sun.reflect.GeneratedMethodAccessor2.invoke(Unknown Source)
[ValidateMDS] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
[ValidateMDS] at java.lang.reflect.Method.invoke(Method.java:597)
[ValidateMDS] at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:105)
[ValidateMDS] at org.apache.tools.ant.Task.perform(Task.java:348)
[ValidateMDS] at org.apache.tools.ant.Target.execute(Target.java:357)
[ValidateMDS] at org.apache.tools.ant.Target.performTasks(Target.java:385)
[ValidateMDS] at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1329)
[ValidateMDS] at org.apache.tools.ant.Project.executeTarget(Project.java:1298)
[ValidateMDS] at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:41)
[ValidateMDS] at org.apache.tools.ant.Project.executeTargets(Project.java:1181)
[ValidateMDS] at org.apache.tools.ant.Main.runBuild(Main.java:698)
[ValidateMDS] at org.apache.tools.ant.Main.startAnt(Main.java:199)
[ValidateMDS] at org.apache.tools.ant.launch.Launcher.run(Launcher.java:257)
[ValidateMDS] at org.apache.tools.ant.launch.Launcher.main(Launcher.java:104)
[ValidateMDS] Caused by: javax.naming.ServiceUnavailableException [Root exception is java.net.UnknownHostException: stpcy05]
[ValidateMDS] at weblogic.jndi.internal.ExceptionTranslator.toNamingException(ExceptionTranslator.java:34)
[ValidateMDS] at weblogic.jndi.WLInitialContextFactoryDelegate.toNamingException(WLInitialContextFactoryDelegate.java:783)
[ValidateMDS] at weblogic.jndi.WLInitialContextFactoryDelegate.getInitialContext(WLInitialContextFactoryDelegate.java:365)
[ValidateMDS] at weblogic.jndi.Environment.getContext(Environment.java:315)
[ValidateMDS] at weblogic.jndi.Environment.getContext(Environment.java:285)
[ValidateMDS] at weblogic.jndi.WLInitialContextFactory.getInitialContext(WLInitialContextFactory.java:117)
[ValidateMDS] at javax.naming.spi.NamingManager.getInitialContext(NamingManager.java:667)
[ValidateMDS] at javax.naming.InitialContext.getDefaultInitCtx(InitialContext.java:288)
[ValidateMDS] at javax.naming.InitialContext.init(InitialContext.java:223)
[ValidateMDS] at javax.naming.InitialContext.<init>(InitialContext.java:197)
[ValidateMDS] at weblogic.management.remote.common.ClientProviderBase.makeConnection(ClientProviderBase.java:169)
[ValidateMDS] ... 21 more
[ValidateMDS] Caused by: java.net.UnknownHostException: stpcy05
[ValidateMDS] at java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method)
[ValidateMDS] at java.net.InetAddress$1.lookupAllHostAddr(InetAddress.java:849)
[ValidateMDS] at java.net.InetAddress.getAddressFromNameService(InetAddress.java:1200)
[ValidateMDS] at java.net.InetAddress.getAllByName0(InetAddress.java:1153)
[ValidateMDS] at java.net.InetAddress.getAllByName(InetAddress.java:1083)
[ValidateMDS] at java.net.InetAddress.getAllByName(InetAddress.java:1019)
[ValidateMDS] at weblogic.rjvm.RJVMFinder.getDnsEntries(RJVMFinder.java:422)
[ValidateMDS] at weblogic.rjvm.RJVMFinder.findOrCreateInternal(RJVMFinder.java:192)
[ValidateMDS] at weblogic.rjvm.RJVMFinder.findOrCreate(RJVMFinder.java:170)
[ValidateMDS] at weblogic.rjvm.ServerURL.findOrCreateRJVM(ServerURL.java:153)
[ValidateMDS] at weblogic.jndi.WLInitialContextFactoryDelegate$1.run(WLInitialContextFactoryDelegate.java:344)
[ValidateMDS] at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:363)
[ValidateMDS] at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:147)
[ValidateMDS] at weblogic.jndi.WLInitialContextFactoryDelegate.getInitialContext(WLInitialContextFactoryDelegate.java:339)
[ValidateMDS] ... 29 more




My question is: how can we catch the UnknownHostException here?
Please let me know.
Thanks

Does that help? BTW, How do I use getRootCause() method? Is there an example?

Thanks

[Henry Wong]

Does that help?

To be blunt... no.

The purpose of code tags, is so that formatting would be preserved. With formatting, it would (much) easier to read and understand the source. You have absolutely no formatting in your code whatsoever. I am assuming that you don't actually write code like this, because it's very difficult to read, much less be able to understand and modify it.

Henry

[Paul Clapham]

As for "can we catch the UnknownHostException", you can catch that exception in any code that you write. But I don't think there's any such code in the stack trace you posted, is there? In which case your best bet is to just fix the configuration entries which cause this expression to be thrown.

[Henry Wong]

BTW, How do I use getRootCause() method? Is there an example?

Basically, when an exception is created, one of the options is to define an exception that is the cause of that exception. So, for example, you have a method that returns IO Exceptions, but the trigger of the IO Exception was another exception; in which case, you create and throw an IO exception, but set as the cause the exception that you caught while doing your processing.

It's not complicated, it is just a piece of data attached to the exception -- except that this piece of data is another exception.

Henry

[Adam Michalik]

First, as far as I know the class Exception does not have the method getRootCause(), only getCause(). So what you would need is catch the IOException (or Exception) and iterate down the exception chain using getCause() until you find an exception of class UnknownHostException. To facilitate this you may wish to use ExceptionUtils from Apache Commons Lang - it has a getRootCause method and indexOfThrowable/indexOfType methods that let you specify the Exception class you are looking for.