Error "No such instance method:java.util.Enumeration org.apache.log4j.Logger.getAllAppenders()" when run JWebSoketBundle in apache-servicemix 4.5.2

Question

I want to embed JWebSocket to osgi environment(apache-servicemix 4.5.2 for example). I did following steps:

• I drop jWebSocketServer-Bundle-1.0.jar to deploy folder of servicemix.
• I create another bundle to call main function of JWebSocketServer class

But when the my bundle runs, it raises above exception. I try to debug to find the problem, I found that has an error on line 112 of JSocketFactory.java

109 if (lDebug) {
110     Logger lLogger = mLog.getRootLogger();
111     String lAppenderStr = "";
112     Enumeration lAppenders = lLogger.getAllAppenders()**; 

Logger does not have getAllAppenders() method. I guest log4j of service mix overrode log4j in jWebSocketServer-Bundle-1.0.jar, but I am not sure about it.

Can you please help me ? thank you

here is my code in MyActivator class to call JWebSocketSer

public class MyActivator implements BundleActivator {

public void start(BundleContext bundleContext) throws Exception
{
    JWebSocketServer.main(null);
}

public void stop(BundleContext bundleContext) throws Exception
{
}

}

Answer 1

Please make sure that both things are using compatible log4j versions. I've check Karaf 2.3.3 and it embeds Log4j 1.2.15. What doesn't work and will cause lots of problems is JWebSocketServer packaging which is a "fat jar". You have log4j (and junit by the way) again embedded in JWebSocketServer.jar.

If you drop something to drop plain JAR to Karaf deploy it gets wrapped in bundle which exports all contents and have Dynamic-ImportPackage. To avoid your issue you may need to repackage jwebsocket.

Answer 2

As ServiceMix/Karaf do use Pax-Logging to provide logging capabilities out of the Box, this isn't available. I guess you have to make sure JWebSocketSer isn't requiring the Appenders. If you want to add custom Appenders this can be done in different ways. Register a Appender as a Service or attach a Fragment-Bundle to the Pax-Logging implementation Bundle, which contains this appender.