유틸리티 배열 활용

#array.html
<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
</head>
<body>
<h1>Arrays</h1>
<ul>
  <li>username = <span th:text="${userA.username}"></span></li>
  <li>age = <span th:text="${userA.age}"></span></li>
</ul>
<h1>LocalDateTime - Utils</h1>
<ul>
  <li>${#arrays.toStringArray(userA)} = <span th:text="${#arrays.toStringArray(userA)}"></span></li>
  <li>${#arrays.toIntegerArray(userA)} = <span th:text="${#arrays.toIntegerArray(userA)}"></span></li>
  <li>${#arrays.toLongArray(userA)} = <span th:text="${#arrays.toLongArray(userA)}"></span></li>
  <li>${#arrays.toDoubleArray(userA)} = <span th:text="${#arrays.toDoubleArray(userA)}"></span></li>
  <li>${#arrays.toFloatArray(userA)} = <span th:text="${#arrays.toFloatArray(userA)}"></span></li>
  <li>${#arrays.toBooleanArray(userA)} = <span th:text="${#arrays.toBooleanArray(userA)}"></span></li>
</ul>
</body>
</html>

@GetMapping("/array")
public String array(Model model) {
    User userA = new User("userA", 10);
    User userB = new User("userB", 20);

    model.addAttribute("userA", userA);
    model.addAttribute("userB", userB);

    return "basic/array";
}

@Data
static class User {
    private String username;
    private int age;

    public User(String username, int age) {
        this.username = username;
        this.age = age;
    }
}

이렇게 했을 때

Caused by: java.lang.IllegalArgumentException: Cannot convert object of class "hello.thymeleaf.basic.BasicController$User" to an array of Class

이런 에러가 뜨는데 왜 에러가 발생하며, 어떻게 활용하면 될까요?

인프런 커뮤니티 질문&답변