java.lang.AbstractMethodError: org.slf4j.impl.Log4jLoggerAdapter.log

Question

i have written a example for login using gwt tool with hibernate and spring integration. getting this error-

Initializing App Engine server SLF4J: The requested version 1.5.8 by your slf4j binding is not compatible with [1.6] SLF4J: See http://www.slf4j.org/codes.html#version_mismatch for further details. Module setup completed in 579 ms java.lang.AbstractMethodError: org.slf4j.impl.Log4jLoggerAdapter.log(Lorg/slf4j/Marker;Ljava/lang/String;ILjava/lang/String;[Ljava/lang/Object;Ljava/lang/Throwable;)V at org.eclipse.jetty.util.log.JettyAwareLogger.log(JettyAwareLogger.java:620) at org.eclipse.jetty.util.log.JettyAwareLogger.debug(JettyAwareLogger.java:206) at org.eclipse.jetty.util.log.Slf4jLog.debug(Slf4jLog.java:89) at org.eclipse.jetty.util.component.Container.add(Container.java:206) at org.eclipse.jetty.util.component.Container.update(Container.java:169) at org.eclipse.jetty.util.component.Container.update(Container.java:111) at org.eclipse.jetty.server.Server.setConnectors(Server.java:200) at org.eclipse.jetty.server.Server.addConnector(Server.java:174) at com.google.gwt.dev.codeserver.WebServer.start(WebServer.java:117) at com.google.gwt.dev.codeserver.CodeServer.start(CodeServer.java:101) at com.google.gwt.dev.codeserver.CodeServer.main(CodeServer.java:71) at com.google.gwt.dev.codeserver.CodeServer.main(CodeServer.java:49) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:606) at com.google.gwt.dev.shell.SuperDevListener$1.run(SuperDevListener.java:112)

jars i have used these jars---------

thanks in advance

Answer 1

AbstractMethodError can only occur at run time if the definition of some class has incompatibly changed since the currently executing method was last compiled.

Seems like the slf4j-api version you have is higher than the slf4j binding version (such as slf4j-jdk14.jar or slf4j-log4j12.jar used to bind slf4j to an underlying logging framework).

For example - slf4j-api 1.7.6 along with slf4j-log4j12-1.5.8 will throw the same error.

You would need to syn the version of both slf4j apis and its binding jar verson.

Answer 2

Mostly its a libraries confilict, what that means there is a library uses log4j with version 1.5.8, and you have imported log4j 1.6.

2 things to try: 1- remove the log4j 1.6 from your imported jars. 2- replace log4j 1.6 jar file with log4j 1.5.8 jar file.

Hope that will help :)