[자바] this와 파라미터의 이해 !!

public class EventTest2 extends Frame {
	Button btn;

	public EventTest2() {
		setTitle("버튼 클릭쿨릭");
		setLayout(new FlowLayout());
		btn = new Button("버튼액션");
		add(btn);

		setSize(300, 300);
		setVisible(true);

		A a = new A(this);
		// this <--EventTest2를 다 가져오겠어
		btn.addActionListener(a);
		// 메소드호출: method(데이터)
		// 생성자호출: new A( 203호 )
	}

	public static void main(String[] args) {
		new EventTest2(); // 203호
	}
}

public class A implements ActionListener {
	Frame f;
	EventTest2 event2;

	public A(Frame f) {
		// EventTest2 f=new EventTest2();
		// Frame f= new EventTest2(); <--자식이니까
		System.out.println(f);
		this.f = f;
	}

	@Override
	public void actionPerformed(ActionEvent e) {
		f.setTitle("변경");
		// =EventTest2.setTitle();
	}
}