Spring 类级别验证和 Thymeleaf

Question

我正在学习 Spring Framework 和 Thymeleaf。我已经知道如何使用类似${#fields.errors("xx")}. 但是，我对如何在 Thymeleaf 中显示对象错误消息感到困惑。

这是我的UserForm类：

@PasswordMatches
public class UserForm {
    @NotNull
    @NotEmpty
    private String username;
    @NotNull
    @NotEmpty
    private String password;
    @NotNull
    @NotEmpty
    private String matchingPassword;
    @NotNull
    @NotEmpty
    @ValidEmail
    private String email;

    /* setter and getter methods */

这是我的PasswordMatches注释：

@Target({ElementType.TYPE, ElementType.FIELD, ElementType.ANNOTATION_TYPE}) 
@Retention(RetentionPolicy.RUNTIME)
@Constraint(validatedBy = PasswordMatchesValidator.class)
@Documented
public @interface PasswordMatches { 
    String message() default "Passwords don't match";
    Class<?>[] groups() default {}; 
    Class<? extends Payload>[] payload() default {};
}

class PasswordMatchesValidator implements ConstraintValidator<PasswordMatches, Object> {  
    @Override
    public void initialize(PasswordMatches constraintAnnotation) {       
    }

    @Override
    public boolean isValid(Object obj, ConstraintValidatorContext context){   
        UserDto user = (UserDto) obj;
        return user.getPassword().equals(user.getMatchingPassword());    
  }     
}

这是我的控制器方法：

@RequestMapping(value="/registration", method=RequestMethod.POST)
public ModelAndView registerUserAccount(@ModelAttribute("user") @Valid UserForm userForm,
          BindingResult result, WebRequest request, Errors errors) {
    if (!result.hasErrors()) {
        return new ModelAndView("registerSuccess");
    }
    else {
        return new ModelAndView("registration", "user", userForm);
    }
}

现在这是我的问题：如果密码字段和confirmPass字段不匹配，我如何获得 Thymeleaf 中类级别注释返回的默认错误消息？

Answer 1

我知道这是旧帖子，但我也遇到了这个问题，这是解决方案（也许它也会帮助其他人）：将 PasswordMatchesValidator 修改为：

class PasswordMatchesValidator implements ConstraintValidator<PasswordMatches, Object> {  
@Override
public void initialize(PasswordMatches constraintAnnotation) {       
}

@Override
public boolean isValid(Object obj, ConstraintValidatorContext context){   
    UserDto user = (UserDto) obj;
    boolean isValid = user.getPassword().equals(user.getMatchingPassword());
    if(!isValid){
         context.disableDefaultConstraintViolation();
        context.buildConstraintViolationWithTemplate(context.getDefaultConstraintMessageTemplate())
                .addPropertyNode( "matchingPassword" ).addConstraintViolation();
    }
    return isValid;

}

它将验证结果绑定到您的“matchingPassword”属性。所以在你的 thymeleaf 模板中，我们是这样的：

${#fields.errors("matchingPassword")}

Answer 2

将其添加到form标签内：

<p data-th-each="err : ${#fields.allErrors()}" data-th-text="${err}" class="error">
  Invalid input.
</p>