How to redirect java.util.logging to a file?

Question

I have a java program using an external library. The main program uses log4j to log its messages and the library uses java.util.logging .

My problem is that log messages from the external library and the main program are mixed in the console.

I would like to redirect all log messages from the external library to a file. I tried to do that with a logging.properties file:

handlers= java.util.logging.FileHandler
.level= INFO
java.util.logging.FileHandler.pattern = foo.log
java.util.logging.FileHandler.formatter = java.util.logging.XMLFormatter

This file is initialized with:

System.setProperty("java.util.logging.config.file", "logging.properties");

Unfortunately, log messages from the external library keep appearing in the console. Should I use something like slf4j to intercept log messages from java.util.logging ?

Thank you for your time.

Answer 1

Here's some code from one of my programs. This also does automatic rotation. The config class is my own that's read from a properties files. You can just replace that with your own values.

Logger rootLogger = Logger.getLogger(""); 
logHandler = new FileHandler(config.getLogFile(), 
                             config.getLogRotateSize()*1024*1024, 
                             config.getLogRotateCount(), false); 
logHandler.setFormatter(new SimpleFormatter()); 
logHandler.setLevel(Level.INFO); 
rootLogger.removeHandler(rootLogger.getHandlers()[0]); 
rootLogger.setLevel(Level.INFO); 
rootLogger.addHandler(logHandler); 

Note this is for a stand-alone program. Any application server has it's own logging configuration tools. The program can also change the formatter and levels on the fly if a dynamic debug mode is desired.