Java DefaultShutdownHook-class And Method Code Example

Here is an example of how to use the DefaultShutdownHook class from the logback library in Java:

import ch.qos.logback.core.DefaultShutdownHook;
import ch.qos.logback.core.util.StatusPrinter;
import org.slf4j.LoggerFactory;

public class Example {
    public static void main(String[] args) {
        // Perform some logging
        Logger logger = (Logger) LoggerFactory.getLogger("ExampleLogger");
        logger.debug("This is a debug message.");"This is an info message.");
        logger.warn("This is a warn message.");
        logger.error("This is an error message.");

        // Register the shutdown hook
        DefaultShutdownHook hook = new DefaultShutdownHook();

        // ... perform some more logging and application tasks

        // Exit the application

This example shows how to use the DefaultShutdownHook class in a Java application that uses logback as the logging framework. The example logs some messages using the logger and then registers the DefaultShutdownHook with the JVM's runtime. The setContext method is used to set the context of the hook to the logger context of the ExampleLogger.

The DefaultShutdownHook class is responsible for shutting down the logging system when the JVM exits. The hook will call the stop method of the logging context, which will close any remaining appenders, which are left open.

After the hook is registered, the application continues to perform some more logging and tasks, then when the System.exit() is called, the hook will be invoked before the JVM exits, it will stop the log context, and make sure the logs are flushed and closed properly.

Please note that

  • You should import the relevant classes for logback
  • The above code is just an example and it does not include the full context of a logging application.
  • The System.exit() call is just an example, you can use any other way to shutdown the application
  • You can also check the status of your logback context by calling StatusPrinter.print(logger.getLoggerContext()); it will print the current status of the logback context, which is useful for debugging