Seems the original went missing, again. > -----Original Message----- > From: Geoff Soutter [mailto:[EMAIL PROTECTED]] > Sent: Tuesday, 26 March 2002 3:46 PM > To: 'Orion Interest List' > Cc: [EMAIL PROTECTED] > Subject: FYI/PATCH: Log4j bug masks part of Orion's stack traces > > > Hi there, > > I've been having a weird problem with parts of my stack > traces disappearing. > > After a few hours mucking around I've tracked it down to a > bug in log4j that I thought you may all wish to be aware of. > > This shows up when you attempt to log an OrionRemoteException > in an application client which has been thrown from a session bean. > > If I call System.out.printStackTrace() I get: > > at com.evermind.server.ejb.EJBUtils.getUserException(.:207) > at > <mySessionBean>_StatelessSessionBeanWrapper3.<mySessionBeanMet > hod>(<mySe > ssionBean>_StatelessSessionBeanWrapper3.java:153) > at java.lang.reflect.Method.invoke(Native Method) > at com.evermind._dq._fs(.:79) > at com.evermind._bt.run(.:62) > at connection to localhost/127.0.0.1 as admin > at > com.evermind._dn.EXCEPTION_ORIGINATES_FROM_THE_REMOTE_SERVER(.:1447) > at com.evermind._dn.invokeMethod(.:1370) > at com.evermind._yp.invoke(.:53) > at __Proxy2.<mySessionBeanMethod>(Unknown Source) > > But if I log the same exception through log4j I get only: > > at > com.evermind._dn.EXCEPTION_ORIGINATES_FROM_THE_REMOTE_SERVER(.:1447) > at com.evermind._dn.invokeMethod(.:1370) > at com.evermind._yp.invoke(.:53) > at __Proxy2.<mySessionBeanMethod>(Unknown Source) > > Turns out the reason for this is that there is a bug in the > way log4j deals with stack traces. In log4j, stace track > formatting is handled by a class called ThrowableInformation. > It contains a subclass of PrintWriter called VectorWriter > which only overrides the println() - all the other methods > are effectively disabled. This class is passed into > Throwable.printStackTrace(). Unfortunately, Orion's implementation of > OrionRemoteException.printStackTrace() is calling print() rather than > println() to pass part of the remote part of the stack trace > across. Thus, this part of the stack trace is simply thrown > away. Ouch. > > This is a bug which impacts Orion and potentially any other > user of log4j which, in general, wishes to override the way that > printStackTrace() works. It has been reported before on the > log4j developers list > (http://www.mail-archive.com/log4j-dev@jakarta.apache.org/msg0 > 0926.html) > , but it appears Ceki is too busy to fix it :-). > > Note, I'm using log4j 1.x at the moment but I had a quick > check of the CVS repository and it appears the bug is in > latest stuff as well. > > I created a simplistic new version of > ThrowableInformation.getThrowableStrRep(), which sucks the > entire stack trace into a buffer and then parses it into > individual lines. It's probably kinda slow compared to the > old version, but at least it fixes the bug. I've included it > if you are interested. > > public > String[] getThrowableStrRep() { > if(rep != null) { > return (String[]) rep.clone(); > } else { > // NOTE: This is not particularly fast. This probably > needs to be > // re-architected to use JDK1.4's new parsed stack > trace stuff anyway, > // so I consider this to be only a temporary solution. > > // First, obtain the _entire_ stack trace as a string > CharArrayWriter caw = new CharArrayWriter(); > PrintWriter pw = new PrintWriter(caw); > throwable.printStackTrace(pw); > pw.flush(); > String trace = caw.toString(); > // Parse it into individual lines. > // This should handle both Win32 and Unix EOL markers > (hopefully). > StringTokenizer tok = new StringTokenizer(trace, "\r\n"); > Vector v = new Vector(); > while (tok.hasMoreTokens()) { > v.add(tok.nextToken()); > } > // Convert the result into an array, without using an > 1.2 functionality > int len = v.size(); > rep = new String[len]; > for(int i = 0; i < len; i++) { > rep[i] = (String) v.elementAt(i); > } > return rep; > } > } > > Cheers > > Geoff > > > -- > To unsubscribe, e-mail: > <mailto:log4j-dev-> [EMAIL PROTECTED]> > For > additional commands, > e-mail: <mailto:[EMAIL PROTECTED]> > >
