@Controller
public class FormController {
    
    @PostMapping("/submitForm")
    public String handleFormSubmission(FormData formData, RedirectAttributes redirectAttributes) {
        // 处理表单数据
        String result = processForm(formData);
        
        // 将结果添加到重定向属性中
        redirectAttributes.addFlashAttribute("result", result);
        
        // 重定向到结果页面
        return "redirect:/resultPage";
    }
    
    @GetMapping("/resultPage")
    public String showResultPage() {
        return "result";
    }
}

// 错误示例 - 会导致循环
@PostMapping("/submit")
public String handleSubmit() {
    return "redirect:/submit";
}

// 正确示例
@PostMapping("/submit")
public String handleSubmit() {
    return "redirect:/result";
}

@PostMapping("/upload")
public String handleFileUpload(@RequestParam("file") MultipartFile file, 
                              RedirectAttributes redirectAttributes) {
    String fileId = fileService.store(file);
    redirectAttributes.addFlashAttribute("message", "上传成功!");
    return "redirect:/files/" + fileId;
}

@PostMapping("/checkout")
public String processCheckout(Order order, RedirectAttributes redirectAttributes) {
    String orderId = orderService.process(order);
    redirectAttributes.addFlashAttribute("orderId", orderId);
    return "redirect:/orderConfirmation";
}