Turn off java.util.logging for a specific package programmatically

Question

I am using an SDK that uses Apache CXF internally. Apache CXF uses the java.util.logging package for logging by default.

I want to change the logging level from INFO to WARNING or turn it off completely. Can I do this programmatically in the main method of my application?

Answer 1

There is a way to do this programatically, but it's not intuitive. Changing to SLF4J or Log4J may be better if you end up needing control at a a finer level or over multiple classes

The issue is that Loggers are cached using WeakReferences. From the time you call Logger.setLevel() until the Logger is actually used, it may be GC'ed. So, the Logger that logs isn't the Logger you set the level on! This is especially true in frameworks where there is a lot of GC at startup.

The solution is to programatically set the configuration, not the actual Loggers.

String logConfig = ".level=" + java.util.logging.Level.INFO + '\n';
logConfig += "handlers=java.util.logging.ConsoleHandler\n";
// ensure ConsoleHandler does not filter
logConfig += "java.util.logging.ConsoleHandler" + ".level=" + java.util.logging.Level.FINEST + '\n';

//set your custom levels
logConfig += "org.apache.cxf" + ".level=" + java.util.logging.Level.WARNING + "\n";

try {
  java.util.logging.LogManager.getLogManager().readConfiguration(new java.io.ByteArrayInputStream(logConfig.getBytes("UTF-8")));
  // no need to close ByteArrayInputStream -- it is a no-op
}
catch (IOException ioe) {
  System.err.println("cannot fully configure logging");
  ioe.printStackTrace();
}

Note there are a few issues with this approach:

1. You are overwriting the built-in configuration, so you have to set the root handler. If you set -Djava.util.logging.config.file, it will also be overwritten.
2. Total hack - might not be maintainable or understandable later.
3. Your config string has to be valid. Note all lines have to end with \n.
4. Has to be called very early, preferably the first line in main(). If this is not possible, you may also need to iterate all the existing Loggers and update their config using setLevel() too.

Answer 2

The link below from Apache CXF has a well understood documentation whether it's java.util.logging or log4j or sl4j:

http://cxf.apache.org/docs/general-cxf-logging.html

It would be very easy if you are using log4j.

You can configure log4j for Apache CXF and then append something like as follows in log4j.properties file which will turn off apache cxf logging.

log4j.apache.cxf = WARN