局部角部类 AvA public void start( final double rate) class InterestAdderimplements Action Listener public void action Performed(Action Eventevent) double interest= balance x rate/100 balance + interest; Number Format formatter Number format get currencylnstanceo System. out. println(balance="+ formatter format(balance)); 3 ction Listener adder= new InterestAddero; Timert= new Timer(1000, adder); t start; JAVA局部内部类 public void start( final double rate) { class InterestAdder implements ActionListener { public void actionPerformed(ActionEvent event) { double interest = balance * rate / 100; balance += interest; NumberFormat formatter = NumberFormat.getCurrencyInstance(); System.out.println("balance=" + formatter.format(balance)); } } ActionListener adder = new InterestAdder(); Timer t = new Timer(1000, adder); t.start(); }