a way to use log4j pass values like java -DmyEnvVar=A_VALUE to my code
- by raticulin
I need to pass some value to enable certain code in may app (in this case is to optionally enable writing some stats to a file in certain conditions, but it might be anything generally).
My java app is installed as a service. So every way I have thought of has some drawbacks:
Add another param to main(): cumbersome as customers already have the tool installed, and the command line would need to be changed every time.
Adding java -DmyEnvVar=A_VALUE to my command line: same as above.
Set an environment variable: service should at least be restarted, and even then you must take care of what user is the service running under etc.
Adding the property in the config file: I prefer not to have this visible on the config file so the user does not see it, it is something for debugging etc.
So I thought maybe there is some way (or hack) to use log4j loggers to pass that value to my code. I have thought of one way already, although is very limited:
Add a dummy class to my codebase com.dummy.DevOptions
public class DevOptions {
public static final Logger logger = Logger.getLogger(DevOptions.class);
In my code, use it like this:
if (DevOptions.logger.isInfoEnabled()){
//do my optional stuff
}
//...
if (DevOptions.logger.isDebugEnabled()){
//do other stuff
}
This allows me to use discriminate among various values, and I could increase the number by adding more loggers to DevOptions. But I wonder whether there is a cleaner way, possibly by configuring the loggers only in log4j.xml??
