정보처리기사 실기 · 2021년 3회 · 20번

class Connection {
    private static Connection _inst = null;
    private int count = 0;
    static public Connection get() {
        if (_inst == null) {
            _inst = new Connection();
            return _inst;
        }
        return _inst;
    }
    public void count() { count++; }
    public int getCount() { return count; }
}

public class testcon {
    public static void main(String[] args) {
        Connection conn1 = Connection.get();
        conn1.count();
        Connection conn2 = Connection.get();
        conn2.count();
        Connection conn3 = Connection.get();
        conn3.count();
        System.out.print(conn1.getCount());
    }
}