Hello,
The problem has been identified. It is basically a backward compatibility problem of the worst kind: everything appears ok at compile time only to blow up at your face at runtime. The symptom =========== Source code will compile fine using either log4j-1.1.3.jar or log4j-1.2alphaX.jar. However, code compiled with log4j-1.1.3.jar will not run with log4j-1.2alphaX.jar and vice versa. Reason ====== The compiler is forgiving on the return type of a method whereas the java runtime is not. Solution ======== None yet. See the attached file surprise.zip to have a better understanding of the exact nature of the problem. At 22:29 08.02.2002 -0500, Chris Haddad wrote: >Ceki - > >This may help to outline the issue that developers may experience with >the recent log4j changes if libraries are built using different versions >of lo4j libraries. > >Tom's suggestion of building axis.jar and the Axis client with the same >log4j file solves the runtime exception. Thanks for the tip Tom. > >The exception appears when Axis client code is build using a lo4j.jar >file that is different than the one used to build the Axis.jar file. It >doesn't matter if only a single lo4j jarfile is available at runtime. > >Is the exception (when different log4 versions are defined at build >time) due to the static declaration of the Category property? Does the >JDK1.3 java compiler optimize the declaration so that there is a >run-time library dependency? It is my understanding that the dependency >of Category changes between the versions even though the outward >getInstance() signature used in the Axis codebase remains constant. > >The interop issue is when libraries (for example, Axis.jar and >MyWebServiceClient.jar) are layered (MyWebService code calls Axis code), >both use log4j, and have been built using different versions of log4j. >In this use case, there is no backward compatibility. > >===== >The gory details: > >The exception arises when axis.jar is built against log4j-core.jar (the >distribution version) and then used in conjunction with an Axis client >built against log4j-1.2alpha7.jar. For some reason, when the client >calls the Axis layer, there is an initialization exception if the >distribution jar for log4j is log4j-1.2alpha7.jar and not log4j-core. > > >Here's the exception thrown: > >Exception in thread "main" java.lang.NoSuchMethodError > > at org.apache.axis.handlers.BasicHandler.<clinit>(Unknown >Source) > at org.apache.axis.client.Service.getAxisClient(Unknown Source) > > at org.apache.axis.client.Service.<init>(Unknown Source) > > >To recap, if one compiles the main branch of xml-axis (using log4j-core) >to obtain axis.jar, builds an Axis client (using log4j-1.2alpha7.jar) >and runs the client with a classpath of axis.jar:log4j-1.2alpha7.jar, a >runtime exception will be thrown when BasicHandler is instantiated. > > >The offending line might be: > >static Category category = > Category.getInstance(BasicHandler.class.getName()); > > >This exception does not occur if the identical log4j jarfile is used for >both the Axis and client build. > >Thanks for your help, > >/Chris > >-----Original Message----- >From: Ceki Gülcü [mailto:[EMAIL PROTECTED]] >Sent: Friday, February 08, 2002 1:01 PM >To: Log4J Developers List; '[EMAIL PROTECTED]' >Cc: '[EMAIL PROTECTED]' >Subject: RE: Interop with Log4j > > >Hi Tom, > >Nothing that would affect backward compatibility was added or removed in >the >recent past. So I can't think of anything. Could you provide more detail > >about the problem >please? Thank you, Ceki > >At 11:36 08.02.2002 -0500, Tom Jordahl wrote: > >Tom Jordahl wrote: > > > The latest log4j from CVS has made a incompatible change from the >previous > > > release version. > > > >Sam Ruby wrote: > > > Have you communicated this to the log4j development team? Such >changes > > > would eventually impact Axis users... I can tell you that the log4j >team > > > takes backwards compatibility very seriously and agressively address >any > > > issues brought to their attention. > > > >I have not in fact communicated with the log4j team. Hi guys! > > > >Here is what I know: If you try to use the nightly build axis.jar with > > >the log4j.jar checked in to our CVS tree, it will fail due to a missing > > >log4j class. I apologize for not having the class name handy. > > > >-- > >Tom Jordahl > >Macromedia > > > >-- > >To unsubscribe, e-mail: ><mailto:[EMAIL PROTECTED]> > >For additional commands, e-mail: ><mailto:[EMAIL PROTECTED]> > >-- >Ceki Gülcü > > > > > > >_________________________________________________________ >Do You Yahoo!? >Get your free @yahoo.com address at http://mail.yahoo.com > > >-- >To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> >For additional commands, e-mail: <mailto:[EMAIL PROTECTED]> -- Ceki Gülcü
surprise.ZIP
Description: Zip archive
