public class ShutdownHook
extends Thread

Emergency shutdown hook for JVM termination. This hook is registered with the JVM Runtime to ensure clean router shutdown even if the normal shutdown process is bypassed or interrupted. It serves as a failsafe mechanism to handle unexpected JVM termination scenarios such as:

• System.exit() calls outside normal shutdown flow
• JVM crashes or fatal errors
• Process termination signals (SIGTERM, etc.)
• Power loss or system shutdown

The hook logs the shutdown event and performs a hard shutdown to prevent the Java Service Wrapper from becoming confused about the router's state. Note: During normal router shutdown, this hook should be cancelled to avoid unnecessary emergency shutdown procedures.