public static void shutdown() throws RuntimeException, IOException {
String shutdownCommand;
String operatingSystem = System.getProperty("os.name");
if ("Linux".equals(operatingSystem) || "Mac OS X".equals(operatingSystem)) {
shutdownCommand = "shutdown -h now";
}
else if ("Windows".equals(operatingSystem)) {
shutdownCommand = "shutdown.exe -s -t 0";
}
else {
throw new RuntimeException("Unsupported operating system.");
}
Runtime.getRuntime().exec(shutdownCommand);
System.exit(0);
}