196. 싱글톤 객체를 여러 번 얻을 때의 상태

1class Counter {
2    private static Counter inst = null;
3    private int n = 0;
4 
5    private Counter() {
6        System.out.print("new ");
7    }
8 
9    static Counter get() {
10        if (inst == null) {
11            inst = new Counter();
12        }
13        return inst;
14    }
15 
16    int add(int k) {
17        n += k;
18        return n;
19    }
20}
21 
22public class Main {
23    public static void main(String[] args) {
24        Counter a = Counter.get();
25        Counter b = Counter.get();
26        a.add(2);
27        b.add(3);
28        System.out.println(a.add(1) + " " + (a == b));
29    }
30}