Re: log4j multiple appenders

=?ISO-8859-1?Q?Arne_Vajh=F8j?= <>
Thu, 05 Nov 2009 22:02:51 -0500
Uli Kunkel wrote:

I'm logging hibernate HQL queries to a log file (file1.log).

The problem is I have a thread which logs to a different file (file2.log).

So I want to change appenders at runtime so that 2 different threads
would simultaniously write hibernate loggs to a different file.

I'm not sure if this will work because I don't know how log4j getLogger
is implemented (if it is singleton or not).
The idea is to call the code below as needed.

Does anyone have any suggestions about this?

public static void setHibernateLogAppender(Logger logger) {



Your problem is not easily solvable.

Logger.getLogger("org.hibernate.SQL") will under normal circumstances
return the same logger for both threads.

If the two threads are not logging at the same time, then
you may be able to change config at runtime (I have not checked
whether your code is good or not).

But it is not a good solution.

I think a better solution would be a custom appender
that are able to log to two files depending on threads
and then at runtime config that appender to match threads
with files.

That will allow concurrent usage.


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