You don't need an init () method in a Java application. It's only required in an applet (you must override it when you extend JApplet). Just add the key listener in the constructor of your JFrame or ...

Java NIO — the New Input/Output API package– was introduced with J2SE 1.4 in 2002. Java NIO’s purpose was to improve the programming of I/O-intensive chores on the Java platform. A decade later, many ...