[JAVA] How to maximize a JFrame through code?

JAVA JFrame 최대화 하기

setExtendedState(getExtendedState()|JFrame.MAXIMIZED_BOTH );

Or

public class Main extends JFrame implements INotiEvent {

    final Main mainFrame = new Main();

    mainFrame.setExtendedState(mainFrame.getExtendedState()|JFrame.MAXIMIZED_BOTH );