타임리프에서 변수를 사용할 때는 변수 표현식을 사용한다.

@GetMapping("/variable")
    public String variable(Model model) {
        User userA = new User("userA", 10);
        User userB = new User("userB", 20);
        
        List<User> list = new ArrayList<>();
        list.add(userA);
        list.add(userB);
        
        Map<String, User> map = new HashMap<>();
        map.put("userA", userA);
        map.put("userB", userB);
        
        model.addAttribute("user", userA);
        model.addAttribute("users", list);
        model.addAttribute("userMap", map);
        return "basic/variable";
    }

<!DOCTYPE html>
<html xmlns:th="<http://www.thymeleaf.org>">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

<h1>SpringEL 표현식</h1>
<ul>Object
    <li>${user.username} =    <span th:text="${user.username}"></span></li>
    <li>${user['username']} = <span th:text="${user['username']}"></span></li>
    <li>${user.getUsername()} = <span th:text="${user.getUsername()}"></span></li>
</ul>
<ul>List
    <li>${users[0].username}    = <span th:text="${users[0].username}"></span></li>
    <li>${users[0]['username']} = <span th:text="${users[0]['username']}"></span></li>
    <li>${users[0].getUsername()} = <span th:text="${users[0].getUsername()}"></span></li>
</ul>
<ul>Map
    <li>${userMap['userA'].username} =  <span th:text="${userMap['userA'].username}"></span></li>
    <li>${userMap['userA']['username']} = <span th:text="${userMap['userA']['username']}"></span></li>
    <li>${userMap['userA'].getUsername()} = <span th:text="${userMap['userA'].getUsername()}"></span></li>

</ul>

<h1>지역 변수 - (th:with)</h1>
<div th:with="first=${users[0]}">
    <p>처음 사람의 이름은 <span th:text="${first.username}"></span></p>
</div>

</body>
</html>

Untitled

지역변수

<div th:with="first=${users[0]}">
    <p>처음 사람의 이름은 <span th:text="${first.username}"></span></p>
</div>

결과

Untitled