Getting Exception org.apache.logging.slf4j.SLF4JLoggerContext cannot be cast to org.apache.logging.log4j.core.LoggerContext

Question

My code is very simple using apache-log4j-2.0.2:

import org.apache.log4j.BasicConfigurator;
import org.apache.log4j.Logger;

public class Log4jtest {
  stati         


        

Answer 1

I was using Maven. I found that declaring my log4j/slf4j dependencies at the top of the list (before Spring Boot, which used logback) fixed the issue.

---

To @TheCodingFrog's credit, adding exclusions to my Spring Boot dependencies also solved the problem. Like so:

    
        ...
        ...
        
            
                log4j
                *
            
            
                org.slf4j
                *
            
            
                org.apache.logging.log4j
                *
            
        
    

---

NOTE: If you care about which logging framework is actually used, one perhaps important difference is that with @TheCodingFrog's method, slf4j retained logback as the binding:

SLF4J: Actual binding is of type [ch.qos.logback.classic.util.ContextSelectorStaticBinder]

whereas, with the method I used, slf4j/log4j was used:

SLF4J: Actual binding is of type [org.slf4j.impl.Log4jLoggerFactory]

---

In case anyone's interested, the log4j/slf4j dependencies I used are:

    log4j
    log4j
    1.2.17


    org.slf4j
    slf4j-api
    1.7.7


    org.slf4j
    slf4j-log4j12
    1.7.7