Spring Boot thymeleaf bad request 400 而不是显示用户错误

Question

我正在尝试使用 post 请求提交表单并首先验证输入。

然而，当我输入错误（例如全部为空）而不是显示错误时，我收到错误请求 (400)。

为了显示错误，我在 HTML.

中使用了 th:if 和 th:errors 标签

如果我提交所有有效输入，就没有问题。

控制器class:

@Controller
@RequestMapping(path = "/order")
public class PurchaseController
{
    @GetMapping(path = "/new")
    public String newOrder(Model model)
    {
        model.addAttribute("Purchase", new Purchase());
        return "neworder";
    }

    @PostMapping(path = "/new")
    public String createPurchase(@Valid @ModelAttribute(name = "Purchase") Purchase purchase)
    {
        int purchaseId = 0;
        try
        {
            purchaseId = PurchaseManager.insertPurchase(purchase);
        }
        catch (SQLException e)
        {
            return "purchaseerror";
        }
        if (purchaseId == 0)
            return "purchaseerror";
        return "redirect:/order/success?id=" + purchaseId;
    }

    @GetMapping(path = "/success")
    public String successPurchase(@RequestParam(required = true, name = "id") int id, Model model)
    {
        model.addAttribute("id", id);
        return "ordersuccess";
    }
}

HTML形式：

<form th:action="@{new}" th:object="${Purchase}" method="post">
                <table>
                    <tr>
                        <td>First name:</td>
                        <td><input type="text" th:field="*{firstName}" /></td>
                        <td th:if="${#fields.hasErrors('firstName')}"
                            th:errors="*{firstName}">Must be filled</td>
                        <td>Last name:</td>
                        <td><input type="text" th:field="*{lastName}" /></td>
                        <td th:if="${#fields.hasErrors('lastName')}"
                            th:errors="*{lastName}">Must be filled</td>
                    </tr>
                    <tr>
                        <td>Adresa:</td>
                        <td><input type="text" th:field="*{address}" /></td>
                        <td th:if="${#fields.hasErrors('address')}" th:errors="*{address}">Must be filled</td>
                    </tr>
                    <tr>
                        <td>ico:</td>
                        <td><input type="text" th:field="*{ico}" /></td>
                        <td th:if="${#fields.hasErrors('ico')}" th:errors="*{ico}">Must be filled</td>
                        <td>dic:</td>
                        <td><input type="text" th:field="*{dic}" /></td>
                        <td th:if="${#fields.hasErrors('dic')}" th:errors="*{dic}">Must be filled</td>
                    </tr>
                    <tr>
                        <td>Email:</td>
                        <td><input type="text" th:field="*{email}" /></td>
                        <td th:if="${#fields.hasErrors('email')}" th:errors="*{email}">Must be filled</td>
                        <td>phone:</td>
                        <td><input type="text" th:field="*{phone}" /></td>
                        <td th:if="${#fields.hasErrors('phone')}" th:errors="*{phone}">Must be filled</td>
                    </tr>
                </table>
                <input type="submit" value="Submit"/>
            </form>

型号class（购买）

public class Purchase
{
    private int id;

    @NotBlank
    @Size(max = 50)
    private String firstName;

    @NotBlank
    @Size(max = 50)
    private String lastName;

    @NotBlank
    @Size(max = 50)
    private String ico;

    @NotBlank
    @Size(max = 50)
    private String dic;

    @NotBlank
    @Size(max = 400)
    private String address;

    @NotBlank
    @Size(max = 50)
    private String email;

    @NotBlank
    @Size(max = 50)
    private String phone;

    private LocalDateTime creationDate;

    ... getters and setters, constructors

如何使用 thymeleaf 显示错误？

编辑： 我设法通过将 BindingResult 参数添加到 Controller class 中的 post 方法并检查是否有任何错误来使其工作。如果是，我 return 表单所在的同一页面（/new 映射），即“neworder”。

return“购买错误”； 可能会造成一些混乱。

@PostMapping(path = "/new")
    public String createPurchase(@Valid @ModelAttribute(name = "Purchase") Purchase purchase, BindingResult result)
    {
        if (result.hasErrors())
        {
            return "neworder";
        }
        int purchaseId = 0;
        try
        {
            purchaseId = PurchaseManager.insertPurchase(purchase);
        }
        catch (SQLException e)
        {
            return "redirect:/purchaseerror";
        }
        if (purchaseId == 0)
            return "redirect:/purchaseerror";
        return "redirect:/order/success?id=" + purchaseId;
    }

Answer 1

如果您在 createPurchase 方法中使用 Model 作为第二个参数，我认为您的问题可以得到解决。然后在您的方法中，您可以执行以下操作来添加消息：

@PostMapping("/add")
    public String addUser(@Valid User user, BindingResult result, Model model) {
        if (result.hasErrors()) {
            return "errors/addUser";
        }
        repository.save(user);
        model.addAttribute("users", repository.findAll()); //this is what you could do.
        return "errors/home";
    }

你的方法会产生如下结果（请自行修改——我只是为了说明目的而写的）：

@PostMapping(path = "/new")
    public String createPurchase(@Valid @ModelAttribute(name = "Purchase") Purchase purchase, Model model)
    {
        int purchaseId = 0;
        try
        {
            purchaseId = PurchaseManager.insertPurchase(purchase);
        }
        catch (SQLException e)
        {
            // todo: don't return right away. Add `model.addAttribute` first.
            return "purchaseerror";
        }
        if (purchaseId == 0) {
            // todo: don't return right away. Add `model.addAttribute` first.
            return "purchaseerror";
        }
        
        return "redirect:/order/success?id=" + purchaseId;
    }

然后您的 Thymeleaf 实现将选择 modelAttribute 中的添加值，您可以从中选择错误（就像您填充它一样）并简单地基于它的逻辑。

您可以按照示例 from here 来更好地理解。请记住，您需要添加到 Model 中，然后才能基于此在 thymeleaf 中布置逻辑。

希望我的回答能解决您的疑问。如果不是，请见谅。

Spring Boot thymeleaf bad request 400 而不是显示用户错误

Spring Boot thymeleaf bad request 400 instead of showing user error

java

spring

thymeleaf

spring-boot