Question

I want to use log4j in my jsp s and servlets. I read apache docs and this blog.I tried as that blog’s second method. and here is my property file

log4j.logger.myapplogger=DEBUG, C, fileappender
 
log4j.additivity.myapplogger=true
log4j.appender.C=org.apache.log4j.ConsoleAppender
log4j.appender.C.layout=org.apache.log4j.PatternLayout
#basic pattern
log4j.appender.C.layout.ConversionPattern=[%c] [%d{dd MMM yyyy - hh:mm:ss}] %5p - %m %n
#advanced pattern (slow)
#log4j.appender.C.layout.ConversionPattern=[%c] [%d{dd MMM yyyy - hh:mm:ss}] %5p - %m - in %M() at line %L of class %C %n 
 
log4j.appender.fileappender=org.apache.log4j.RollingFileAppender
log4j.appender.fileappender.File=${appRootPath}WEB-INF/logs/app_log.log
log4j.appender.fileappender.MaxFileSize=500KB
 
## Keep one backup file
log4j.appender.fileappender.MaxBackupIndex=3
log4j.appender.fileappender.layout=org.apache.log4j.PatternLayout
log4j.appender.fileappender.layout.ConversionPattern=%p %t %c - %m%n
#log4j.appender.C.layout.ConversionPattern=[%c] [%d{dd MMM yyyy - hh:mm:ss}] %5p - %m %n

Here is my servlet Listener

public class ApplicationServletContextListener implements ServletContextListener{

    public void contextInitialized(ServletContextEvent e) {

        ServletContext ctx=e.getServletContext();
      String prefix=ctx.getRealPath("/");
String file="WEB-INF"+System.getProperty("file.separator")+"classes"+System.getProperty("file.separator")+"log4j.properties";

if(file !=null){
PropertyConfigurator.configure(prefix+file);
    System.out.println("Log4J Logging started for application: " + prefix+file);
}else{
System.out.println("Log4J Is not configured for application Application: " + prefix+file);
}  

And console displays “Log4J Logging started for application…” .

Here is my servlet where I try to test.

private Logger log = Logger.getLogger("myapplogger");
 log.error("this is a testign error");  

The console shows the log.But still there is no any log file created under WEB-INF/logs/ .Please let me know where I have to check and how to correct this.

Answer 1

Its because

You have the variable ${appRootPath} in the File property for the append.It has not been set so, its empty.

Since it’s empty, it ends up creating a WEB-INF/logs dir in your home directory, rather than the tomcat webapps/.

Define the property in contextInitialized()

System.setProperty("appRootPath", context.getRealPath("/"));

Restart the servlet container.