如何使用Thymeleaf构建srcset属性

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>

<img src="default.jpg" th:src="@{${device} == 'mobile' ? 'mobile.jpg' : 'desktop.jpg'}"
     th:srcset="@{${device} == 'mobile' ? 'mobile.jpg' : 'desktop.jpg'} 1x,
                @{${device} == 'mobile' ? 'mobile@2x.jpg' : 'desktop@2x.jpg'} 2x">

@Controller
public class MyController {
    
    @GetMapping("/")
    public String index(Model model, HttpServletRequest request) {
        String device = "desktop";
        // 根据实际情况获取设备类型，例如使用User-Agent判断设备类型
        if (isMobileDevice(request)) {
            device = "mobile";
        }
        model.addAttribute("device", device);
        return "index";
    }
    
    private boolean isMobileDevice(HttpServletRequest request) {
        // 判断设备类型的逻辑
        // ...
    }
}