Spring Boot Thymeleaf 自定义验证器不显示错误答案

【问题标题】：Spring Boot Thymeleaf custom validator not showing errorsSpring Boot Thymeleaf 自定义验证器不显示错误
【发布时间】：2018-05-07 18:49:05
【问题描述】：

我的 Thymeleaf 布局有问题，它没有显示自定义注释验证器捕获的验证错误。

控制器：

@RequestMapping(value = "/register", method = RequestMethod.POST)
public String handleRegisterForm(@ModelAttribute("userCreateForm") @Valid UserCreateForm userCreateForm, BindingResult bindingResult, Model model){
    LOGGER.debug("Processing user create form={}, bindingResult={}", userCreateForm, bindingResult);
    model.addAttribute("userCreateForm", new UserCreateForm());
    model.addAttribute("email", userCreateForm.getEmail());
    model.addAttribute("password", userCreateForm.getPassword());
    model.addAttribute("firstName", userCreateForm.getFirstName());
    model.addAttribute("lastName", userCreateForm.getLastName());
    userCreateFormValidator.validate(userCreateForm, bindingResult);
    if (bindingResult.hasErrors()){
        for (int i = 0; i < bindingResult.getAllErrors().size(); i++)
        {
            System.out.println(bindingResult.getAllErrors().get(i).getObjectName());
            System.out.println(bindingResult.getAllErrors().get(i).getCode());
            System.out.println(bindingResult.getAllErrors().get(i).toString());
        }
        return "register";
    }
    try {
        userService.create(userCreateForm);
    } catch (DataIntegrityViolationException | NoSuchAlgorithmException e) {
        bindingResult.reject("email.exists", "Email already exists");
        LOGGER.warn("Exception occurred when trying to save the user, assuming duplicate email", e);
    }

    return "redirect:/login";
}

型号：

public class UserCreateForm {
@NotEmpty
@UniqueEmail
private String email;
@NotEmpty
private String password;
@NotEmpty
private String firstName;
@NotEmpty
private String lastName;

public String getEmail() {
    return email;
}

public void setEmail(String email) {
    this.email = email;
}

public String getPassword() {
    return password;
}

public void setPassword(String password) {
    this.password = password;
}

public String getFirstName() {
    return firstName;
}

public void setFirstName(String firstName) {
    this.firstName = firstName;
}

public String getLastName() {
    return lastName;
}

public void setLastName(String lastName) {
    this.lastName = lastName;
}

验证者：

@Documented
@Target({ElementType.METHOD, ElementType.FIELD})
@Retention(RetentionPolicy.RUNTIME)
@Constraint(validatedBy = UniqueEmailValidator.class)
public @interface UniqueEmail {
String message() default "Account exists!";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
}

class UniqueEmailValidator implements ConstraintValidator<UniqueEmail, String> {

private UserRepository userRepository;

public UniqueEmailValidator(UserRepository userRepository) {
    this.userRepository = userRepository;
}

@Override
public void initialize(UniqueEmail uniqueEmail) {
}

@Override
public boolean isValid(String email, ConstraintValidatorContext context) {
    return email != null && !userRepository.findOneByEmail(email).isPresent();
}
}

百里香代码：

<div class="container" >
<div class="row view-area">
    <div class="col-lg-12">
        <form role="form" name="userCreateForm" th:object="${userCreateForm}" th:action="@{/register}" method="post">
            <div class="row form-group">
                <div class="col-lg-6">
                    <label for="email" class="sr-only">EMAIL</label>
                    <input type="text" th:field="*{email}" id="email" class="form-control" placeholder="EMAIL" required="required" autofocus="autofocus" />
                    <p th:if="${#fields.hasErrors('firstName')}" th:errors="*{firstName}">ERROR!</p>
                </div>
            </div>

当验证器捕获错误时，这是我的控制台输出：

userCreateForm
UniqueEmail
Field error in object 'userCreateForm' on field 'email': rejected value 
[test@test.com]; codes [UniqueEmail.userCreateForm.email,UniqueEmail.email,UniqueEmail.java.lang.String,UniqueEmail]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [userCreateForm.email,email]; arguments []; default message [email]]; default message [Account exists!]

所以你可以看到我的验证器捕获错误并刷新页面。但在那之后，看不到任何错误。我认为我的 Thymeleaf 代码有问题，但我找不到。

【问题讨论】：

你没有把'firstName'和'email'混为一谈吗？

标签： validation spring-mvc spring-boot thymeleaf

【解决方案1】：

就像评论中提到的那样。在您的 tymeleaf 模板中，您的错误消息的属性名称错误。

不正确：

<p th:if="${#fields.hasErrors('firstName')}" th:errors="*{firstName}">ERROR!</p>

正确：

<p th:if="${#fields.hasErrors('email')}" th:errors="*{email}">ERROR!</p>

【讨论】：