Question

I’ve done my best to setup Eclipse and my Java application to use a log4j.properties file. However, it does not seem to be using the properties file and I’m not sure why.

Libraries: slf4j-api-1.6.1, slf4j-jdk14-1.6.1

Within the application the logging works fine. I am able to print info, warnings, and errors into the Eclipse console.

What I would like to be able to do is change the log level to debug and print all logging messages to both the console and a log file.

I have created a log4j.properties file that looks like this:

log4j.rootLogger=DEBUG,console,file
log4j.rootCategory=DEBUG, R, O

# Stdout
log4j.appender.O=org.apache.log4j.ConsoleAppender

# File
log4j.appender.R=org.apache.log4j.RollingFileAppender
log4j.appender.R.File=log4j.log

# Control the maximum log file size
log4j.appender.R.MaxFileSize=100KB

# Archive log files (one backup file here)
log4j.appender.R.MaxBackupIndex=5
log4j.appender.file.File=checkLog.log
log4j.appender.file.threshold=DEBUG

log4j.appender.R.layout=org.apache.log4j.PatternLayout
log4j.appender.O.layout=org.apache.log4j.PatternLayout

log4j.appender.R.layout.ConversionPattern=[%d{ISO8601}]%5p%6.6r[%t]%x - %C.%M(%F:%L) - %m%n
log4j.appender.O.layout.ConversionPattern=[%d{ISO8601}]%5p%6.6r[%t]%x - %C.%M(%F:%L) - %m%n

My directory structure looks like this:

My Project
--src/
----MYProject/
------*.java
--bin/
----MYProject/
------*.class
--log4j/
----log4j.properties

In Eclipse I this this:

Run Configurations -> Classpath (tab) ->, right clicked on User Entries -> Added “log4j” as a new folder, and saved.

Then in my code I call the logger like this (sample code to demonstrate my approach so it may have syntax errors):

package MYProject;
import org.slf4j.LoggerFactory;

public class MyClass{

  final org.slf4j.Logger test_logger = LoggerFactory.getLogger(MyClass.class);

  public MyClass(){}

  public someMethod(){
    test_logger.debug("Some Debug");
    test_logger.info("Some Info");
    test_logger.warn("Some Warning");
    test_logger.error("An Error");
  }

}

I then call someMethod and it prints INFO, WARN, ERROR to the Eclipse console. It won’t print DEBUG and won’t print to a file.

I’d appreciate any suggestions on what I may be doing wrong.

Answer 1

There may be another log4j.properties or log4j.xml file in the classpath ahead of your log4j.properties. Open the run configuration for your project, and add -Dlog4j.debug=true as a VM Argument for your project. This will instruct log4j to print a lot of additional information on the console, including the config file that it is using.