Configuring SLF4J/Logback for a Standalone App

Most examples of SLF4J/Logback you can find on the Internet are about how web applications are configured. But if you have a command line or JavaFX application, you’ll require a different setup. Most probably, you want a local ‘logback.xml’ that is located in your application’s folder or in the home directory of the user. But how do you configure SLF4J/Logback for a Java SE application?

The good news is that there is already a tiny library that does the trick: ext4logback. It allows you simply to specify the location of your ‘logback.xml’ and does all the initialization for you. It also creates a default logback XML configuration if no file exists at startup.

Simply add the dependency to your Maven POM:

<dependency>
    <groupId>org.fuin</groupId>
    <artifactId>ext4logback</artifactId>
    <version>0.2.0</version>
</dependency>

Then you can just initialize the log in your applications ‘main’ method:

/**
 * Starts the application.
 * 
 * @param args
 *            Only optional argument is the 'logback.xml' file path and
 *            name. If no argument is provided it's assumed that the file name 
 *            is 'logback.xml' and it's in the current directory.
 */
public static void main(final String[] args) {
    try {
        // Initializes Logback by reading the XML config file.
        // If the file does not exist, it will be created with some defaults.
        // This is a convenience method that directly uses the main method's arguments.
        new LogbackStandalone().init(args, new NewLogConfigFileParams("your.app.package", "myapp"));
        LOG.info("Application running...");
        // Your code goes here...
        System.exit(0);
    } catch (RuntimeException ex) {
        ex.printStackTrace(System.err);
        System.exit(1);
    }
}