java.lang.ClassNotFoundException: org.apache.log4j.Level

Question

I'm trying to use hibernate 3.5.1 final in a swing application and here are the jars I'm using:

• hibernate-core-3.5.1-Final
• hibernate-entitymanager-3.5.1-Final
• hibernate-jpa-2.0-api-1.0.0.Final
• hibernate-annotations-3.5.1-Final
• hibernate-commons-annotations-3.2.0.Final
• dom4j-1.6.1
• slf4j-api-1.6.4
• slf4j-log4j12-1.6.4

When I try to run the application, I get the following error:

Failed to instantiate SLF4J LoggerFactory
Reported exception:
java.lang.NoClassDefFoundError: org/apache/log4j/Level
    at org.slf4j.LoggerFactory.bind(LoggerFactory.java:128)
    at org.slf4j.LoggerFactory.performInitialization(LoggerFactory.java:108)
    at org.slf4j.LoggerFactory.getILoggerFactory(LoggerFactory.java:279)
    at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:252)
    at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:265)
    at org.hibernate.cfg.Configuration.<clinit>(Configuration.java:165)
    at org.hibernate.ejb.Ejb3Configuration.<clinit>(Ejb3Configuration.java:127)
    at org.hibernate.ejb.HibernatePersistence.createEntityManagerFactory(HibernatePersistence.java:54)
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:48)
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:32)
    at com.xeno.xecamp.desktopManagement.Main.main(Main.java:16)
Caused by: java.lang.ClassNotFoundException: org.apache.log4j.Level
    at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
    ... 11 more
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/log4j/Level
    at org.slf4j.LoggerFactory.bind(LoggerFactory.java:128)
    at org.slf4j.LoggerFactory.performInitialization(LoggerFactory.java:108)
    at org.slf4j.LoggerFactory.getILoggerFactory(LoggerFactory.java:279)
    at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:252)
    at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:265)
    at org.hibernate.cfg.Configuration.<clinit>(Configuration.java:165)
    at org.hibernate.ejb.Ejb3Configuration.<clinit>(Ejb3Configuration.java:127)
    at org.hibernate.ejb.HibernatePersistence.createEntityManagerFactory(HibernatePersistence.java:54)
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:48)
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:32)
    at com.xeno.xecamp.desktopManagement.Main.main(Main.java:16)
Caused by: java.lang.ClassNotFoundException: org.apache.log4j.Level
    at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:248)

Waadt

If you're trying to use symbolic links to attach your jar files, then see #22241276 – Joejoeann

Answer 1

You also need to include the Log4J JAR file in the classpath.

Note that slf4j-log4j12-1.6.4.jar is only an adapter to make it possible to use Log4J via the SLF4J API. It does not contain the actual implementation of Log4J.

Treponema

can you please tell me the maven dependency compatible with the version i am using ? – Waadt

well i just needed log4j-1.2.16.jar – Waadt

adding log4j-1.2.16.jar also solved the problem in my case but slf4j-log4j12-1.6.4.jar didn't – Transeunt

actually adding maven dependency as such was not sufficient in my case, i also had to add the flag: <scope>build</scope> to make it run: <dependency> <groupId>log4j</groupId> <artifactId>log4j</artifactId> <version>1.2.17</version> <scope>build</scope> </dependency> – Hamate

Answer 2

You need to download log4j and add in your classpath.

Sylvan

Answer 3

In my environment, I just added the two files to class path. And is work fine.

slf4j-jdk14-1.7.25.jar
slf4j-api-1.7.25.jar

Sse

Thanks, this worked for me in October 2019. I didn't even need the log jar, the slf4j-jdk took care of it. – Devy

This worked for me today oct 20th 2023. Except that my two files are of higher versions. – Pinko