Log4j wrapper

package daveutil;

import org.apache.log4j.Level;
import org.apache.log4j.Logger;

public class Log4jWrapper {

    /*
     * TRACE, DEBUG, INFO, WARN, ERROR, FATAL
     */
    Level level = Level.DEBUG;

    public static Log4jWrapper LOG;
    
    private Logger logger;
    
    static {
        synchronized(Log4jWrapper.class){
            if(LOG == null){
                LOG = new Log4jWrapper("daveapp");
            }
        }
    }

    private  Log4jWrapper(String logger) {
        this.logger = Logger.getLogger(logger);
    }

    public void log(Object o) {
        logger.log(level, o);
    }
    
    public void log(Object o,Throwable e) {
        logger.log(level, o, e);
    }

    public void log(String callerFCQN,Object o,Throwable e) {
        logger.log(callerFCQN,level, o, e);
    }

    public void trace(Object o) {
        logger.trace(o);
    }
    
    public void trace(Object o,Throwable e) {
        logger.trace(o,e);
    }

    public void debug(Object o) {
        logger.debug(o);
    }
    
    public void debug(Object o,Throwable e) {
        logger.debug(o,e);
    }

    public void info(Object o) {
        logger.info(o);
    }
    
    public void info(Object o,Throwable e) {
        logger.info(o,e);
    }

    public void warn(Object o) {
        logger.warn(o);
    }
    
    public void warn(Object o,Throwable e) {
        logger.warn(o,e);
    }

    public void error(Object o) {
        logger.error(o);
    }
    
    public void error(Object o,Throwable e) {
        logger.error(o,e);
    }

    public void fatal(Object o) {
        logger.fatal(o);
    }
    
    public void fatal(Object o,Throwable e) {
        logger.fatal(o,e);
    }

}

Using log4j wrapper

package daveapp;

import daveutil.Log4jWrapper;

public class TestDaveApp {
    
    public void testDaveApp(){

        System.out.println("Use Log4jWrapper");
        Log4jWrapper.LOG.info("TestDaveApp info");
        
        Log4jWrapper.LOG.info("TestDaveApp info",new Exception("TestDaveApp"));
    }

}

log4j properties configuration
Pattern layout
http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/PatternLayout.html

Property Configurator

http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/PropertyConfigurator.html

All option values admit variable substitution. The syntax of variable substitution is similar to that of Unix shells. The string between an opening "${" and closing "}" is interpreted as a key. The value of the substituted variable can be defined as a system property or in the configuration file itself.

#log4j.rootLogger=debug, stdout, dave, daveutil

log4j.logger.dave=DEBUG,stdout, dave  
log4j.logger.daveutil=DEBUG, stdout, daveutil   
log4j.logger.daveapp=DEBUG, stdout, daveapp  

log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout

# Pattern to output the caller's file name and line number.
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] (%F:%L) - %m%n

log4j.appender.dave=org.apache.log4j.RollingFileAppender
# do not send to other logs
log4j.additivity.dave=false
log4j.appender.dave.File=${weblogic.Name}.dave.log

log4j.appender.dave.MaxFileSize=10KB
# Keep one backup file
log4j.appender.dave.MaxBackupIndex=5

log4j.appender.dave.layout=org.apache.log4j.PatternLayout
log4j.appender.dave.layout.ConversionPattern=%p %t %c - %m%n

log4j.appender.daveutil=org.apache.log4j.RollingFileAppender
# do not send to other logs
log4j.additivity.daveutil=false
log4j.appender.daveutil.File=${weblogic.Name}.daveutil.log

log4j.appender.daveutil.MaxFileSize=10KB
# Keep one backup file
log4j.appender.daveutil.MaxBackupIndex=5

log4j.appender.daveutil.layout=org.apache.log4j.PatternLayout
log4j.appender.daveutil.layout.ConversionPattern=%p %t %c - %m%n

log4j.appender.daveapp=org.apache.log4j.RollingFileAppender
# do not send to other logs
log4j.additivity.daveapp=false
log4j.appender.daveapp.File=${weblogic.Name}.daveapp.log

log4j.appender.daveapp.MaxFileSize=10KB
# Keep one backup file
log4j.appender.daveapp.MaxBackupIndex=5

log4j.appender.daveapp.layout=org.apache.log4j.PatternLayout
log4j.appender.daveapp.layout.ConversionPattern=%p %t %c - %m%n

Using FCQN - fully qualified class name

Log4jWrapper.LOG.log(TestDaveApp.class.getName(),"TestDaveApp info",new Exception("TestDaveApp"));

 INFO  (Log4jWrapper.java:62) - TestDaveApp info


DEBUG (TestDave.java:22) - TestDaveApp info