Caused By: java.lang.NoClassDefFoundError: org/apache/log4j/Logger

Question

I\'ve got an interesting problem in which the org.apache.log4j.Logger class is not found during runtime. I\'m trying to get authorized and that is where it\'s failing:

Answer 1

Based on the stacktrace, an intuit class com.intuit.ipp.aggcat.util.SAML2AssertionGenerator needs a saml jar on the classpath.

A saml class org.opensaml.xml.XMLConfigurator needs on it's turn log4j, which is inside the WAR but cannot find it.

One explanation for this is that the class XMLConfigurator that needs log4j was found not inside the WAR but on a downstream classloader. could a saml jar be missing from the WAR?

The class XMLConfigurator that needs log4j cannot find it at the level of the classloader that loaded it, and the log4j version on the WAR is not visible on that particular classloader.

In order to troubleshoot this, a way is to add this before the oauth call:

System.out.println("all versions of log4j Logger: " + getClass().getClassLoader().getResources("org/apache/log4j/Logger.class") );

System.out.println("all versions of XMLConfigurator: " + getClass().getClassLoader().getResources("org/opensaml/xml/XMLConfigurator.class") );

System.out.println("all versions of XMLConfigurator visible from the classloader of the OAuthAuthorizer class: " + OAuthAuthorizer.class.getClassLoader().getResources("org/opensaml/xml/XMLConfigurator.class") );

System.out.println("all versions of log4j visible from the classloader of the OAuthAuthorizer class: " + OAuthAuthorizer.class.getClassloader().getResources("org/apache/log4j/Logger.class") );

Also if you are using Java 7, have a look at jHades, it's a tool I made to help troubleshooting these type of problems.

In order to see what is going on, could you post the results of the classpath queries above, for which container is this happening, tomcat, jetty? It would be better to put the full stacktrace with all the caused by's in pastebin, just in case.

Answer 2

Check in Deployment Assembly,

I have the same error, when i generate the war file with the "maven clean install" way and deploy manualy, it works fine, but when i use the runtime enviroment (eclipse) the problems come.

The solution for me (for eclipse IDE) go to: "proyect properties" --> "Deployment Assembly" --> "Add" --> "the jar you need", in my case java "build path entries". Maybe can help a litle!