如何返回一条消息(来自Spring)来表示没有找到该信息？

@ResponseStatus(HttpStatus.NOT_FOUND)
public class ResourceNotFoundException extends RuntimeException {
    // 自定义异常类，用于表示资源未找到
}

@GetMapping("/users/{id}")
public User getUser(@PathVariable Long id) {
    User user = userRepository.findById(id)
            .orElseThrow(ResourceNotFoundException::new);
    return user;
}

public class ErrorResponse {
    private String message;
    
    // getter和setter方法
}

@GetMapping("/users/{id}")
public ResponseEntity<?> getUser(@PathVariable Long id) {
    User user = userRepository.findById(id)
            .orElseThrow(() -> new ResponseStatusException(HttpStatus.NOT_FOUND, "User not found"));
    
    // 其他逻辑
    
    return ResponseEntity.ok(user);
}

@ExceptionHandler(ResourceNotFoundException.class)
public ResponseEntity<ErrorResponse> handleResourceNotFoundException(ResourceNotFoundException ex) {
    ErrorResponse errorResponse = new ErrorResponse();
    errorResponse.setMessage("Resource not found");
    return ResponseEntity.status(HttpStatus.NOT_FOUND).body(errorResponse);
}