API para usar funcionalidades do sistema operacional como reiniciar o pc

import java.io.*;


public class TesteRuntime {
	
	public static void main( String[] args ) {
		
		Runtime rt = Runtime.getRuntime();
		Process p = null;
		
		try {
			
			p = rt.exec( "rundll32.exe user.exe,ExitWindows" );
				
			BufferedReader reader = new BufferedReader(
				new InputStreamReader( p.getInputStream() ) );
			String linha;

			while ( ( linha = reader.readLine() ) != null )
            	System.out.println( linha );
			
		} catch ( IOException exc ) {
		}
		
	}
	
}