Java equals

public static void main(String[] args) {
    String str = "{\"ret\":-3,\"errmsg\":\"no session\"}";
    JSONObject obj1 = new JSONObject(str);
    JSONObject obj2 = new JSONObject(str);
    System.out.println(obj1.equals(obj2));
    System.out.println(obj1==obj2);
}

Why both get false ?

System.out.println(obj1.toString().equals(obj2.toString()));