Load java.util.logging.config.file for default initialization

Question

You can dynamically load java.util.logging properties files from a relative path very easily. This is what I put inside a static {} block in my Main class. Put your logging.properties file in the default package and you can access it very easily with the following code.

final InputStream inputStream = Main.class.getResourceAsStream("/logging.properties");
try
{
    LogManager.getLogManager().readConfiguration(inputStream);
}
catch (final IOException e)
{
    Logger.getAnonymousLogger().severe("Could not load default logging.properties file");
    Logger.getAnonymousLogger().severe(e.getMessage());
}

Java logging doesn't search your whole hard disk for a file; there are very simple rules how files are looked up. You want Java to see that the two files belong to each other but you didn't say so anywhere. Since Java sees no connection between the properties file and your class other than that they are in the same folder on your disk, it can't find the file.

-Djava.util.logging.config.file=log.properties only works if the file log.properties is in the current directory of the Java process (which can be pretty random). So you should use an absolute path here.

An alternate solution would be to move the file logging.properties into $JAVA_HOME/lib/ (or edit the file which should be there). In that case, you don't need to set a System property.

util logging does not load from classpath, it needs an absolute path which is why other logging packages like log4j are far easier to configure and better for web apps where it's a pain to get abs paths.

this is not explained at all in the java.util.logging.LogManager doco.