Can Log4j read two properties?

[avseq anthoy]

I can configure log4j.properties in the path when I use log4j to log in a file.

I want to configure two log4.properties , one is for logging to file , and the other is for looging to database.
I don't want to log all information into FILE or Database.
In some occasion , I only want to log in database.
Can log4j runtime read which properties file so that I can choose when to log in file and when to log in database?

[Ulf Dittmer]

You can use two log instances in your code, to which you selectively write. They can still be configured in the same log4j.properties file.

[prateek urmaliya]

You can specify to differnt appender namely

log4j.appender.LOGFILE  

and

log4j.appender.DATABASE

Now you can use the loggers to specify the level info that you want to login to DB or FILE
let's say for your package xyz you want to log debug level and logs beyond but the file you use is only for checking the error level log
so you can achieve this by writing in your log4j

log4j.logger.xyz=debug,DATABASE

log4j.logger.xyz=error,LOGFILE

[ March 24, 2007: Message edited by: prateek urmaliya ]

[Ulf Dittmer]

... you can achieve this by writing in your log4j

log4j.logger.xyz=debug,DATABASE

log4j.logger.xyz=error,LOGFILE

Hmm, are you sure that'll work? log4j.properties is a properties file,
so I would have thought that the second key of the same name overrides the first. Is that not the case?

[prateek urmaliya]

Mea Culpa
Yes it will overwrite,
I think setting threshold for FILE appender to error

log4j.appender.LOGFILE.Threshold=ERROR

and then

log4j.logger.xyz=debug,LOGFILE,DATABASE

will solve it.
Thanks Ulf

[Ulf Dittmer]

log4j.logger.xyz=debug,LOGFILE,DATABASE

will solve it.

Actually, I don't think it will. In that case both appenders will have the same information written to, which is what the original poster didn't want. I think there is no way around using two log instances.

[avseq anthoy]

Thanks for your replying.
It look like that I can't use log4j to log message to different destination.
I will use log4j to log to file , and write a few code by myself to log message to DB like insert a record.
[ March 27, 2007: Message edited by: avseq anthoy ]

[Ulf Dittmer]

It look like that I can't use log4j to log message to different destination.

What have you tried? Did you configure two log instances (as opposed to two log appenders, which was talked about above)?

[Rahul Bhattacharjee]

You can have many appenders configured in only one log4j.properties file and as and when required you can plug different appenders to different loggers.

[avseq anthoy]

My log4j config list as below

   
log4j.rootLogger=INFO,FileAppender,ConsoleAppender
log4j.appender.FileAppender=org.apache.log4j.DailyRollingFileAppender
log4j.appender.FileAppender.layout=org.apache.log4j.PatternLayout
log4j.appender.FileAppender.layout.ConversionPattern=[%d{yyyy MM dd HH:mm:ss}] %-5p %l %20c{1}.%-20M %m%n
log4j.appender.FileAppender.File=C:/test.log
 
log4j.appender.ConsoleAppender=org.apache.log4j.ConsoleAppender
log4j.appender.ConsoleAppender.layout=org.apache.log4j.PatternLayout
log4j.appender.ConsoleAppender.layout.ConversionPattern=[%d{yyyy MM dd HH:mm:ss}] %-5p %l %20c{1}.%-20M %m%n

I use following code to get log instance in my application.

private static final Log log = LogFactory.getLog(ABC.class);

But log will wirte to console and file simultaneously.
How do I configure and use that sometimes I want these message only write to file but sometimes only write to database?

[Paul Clapham]

What is this "sometimes"? Is it like "On this run of the program I want to log to the database, on the next run I want to log to file"? If that's the case you can just configure log4j with the appropriate configuration file when your program starts up.

Or is it like "Now I want the program to start logging to the database, but I don't want to stop it and restart it"?

[Ulf Dittmer]

Avseq,

as I've said before, you need to use two log instances, but what your file shows is two log appenders. Now, you will need two appenders, but unless you also create two instances it's not going to work.

[prateek urmaliya]

Actually, I don't think it will. In that case both appenders will have the same information written to, which is what the original poster didn't want. I think there is no way around using two log instances.

I don't know but it's working for me,

let's say for your package hasta.la.vista.baby you want to log WARN level and logs beyond but the file you use is only for checking the ERROR level log

here is what I am doing ,I am using file appender in both cases
TestLogging.java

package hasta.la.vista.baby;
 
import org.apache.log4j.Logger;
 
// How to use log4j
public class TestLogging {
 
/**
 * Logger for this class
 */
private static final Logger logger = Logger.getLogger(TestLogging.class);
 
public static void main(String args[]) {
// From here on, log away!
logger.debug("life is short");
logger.info("get a beer");
logger.warn("when going gets weird");
logger.error("the weird turns pro");
logger.fatal("to err is human");
logger.fatal("to debug is divine");
}
}

log4j file

log4j.logger.hasta.la.vista.baby=INFO,LOGFILE1,LOGFILE2
 
log4j.appender.LOGFILE1=org.apache.log4j.DailyRollingFileAppender
log4j.appender.LOGFILE1.File=C:/test1.log
log4j.appender.LOGFILE1.Threshold=ERROR
log4j.appender.LOGFILE1.layout=org.apache.log4j.PatternLayout
 
 
log4j.appender.LOGFILE2=org.apache.log4j.DailyRollingFileAppender
log4j.appender.LOGFILE2.File=C:/test2.log
log4j.appender.LOGFILE2.Threshold=WARN
log4j.appender.LOGFILE2.layout=org.apache.log4j.PatternLayout    

test1.log

the weird turns pro
to err is human
to debug is divine    

test2.log

when going gets weird
the weird turns pro
to err is human
to debug is divine    

[ March 28, 2007: Message edited by: prateek urmaliya ]

[Ulf Dittmer]

That's just using different log levels; it can't log selectively to one or the other, which I understood the original poster wanted.

[prateek urmaliya]

hmm..
yes then there is no way but to use two different loggers.

[avseq anthoy]

I use log4j to log to file and database separately successfully.
My solution is that when log level is "FATAL" , log to database.If log level is higher than "INFO" , log to file.

I want to know how to use two different log instance. Because log4j will look up log4j.propeties in the path by itself.
If I want to use two log instance , should I configure two properteis and set the propreties path in the code?
But I don't want to set the properties path in the code apparently.