我一直在尝试让自定义 javax 验证工作(Spring Boot 和 Thymeleaf),但我不知道如何显示错误消息。问题似乎是,“正常”错误(例如 @Size、@NotNull 等)似乎会向绑定结果添加 FieldError。不过,我的自定义验证器会传递一个 ObjectError 。我不知道如何让 Thymeleaf 显示我的自定义错误(这显然已经通过了,因为th:errors="*{*}"
显示它)。
任何帮助是极大的赞赏。
更新:
我现在可以通过显示错误消息
<p th:if="${#fields.hasErrors('${user}')}" th:errors="${user}"></p>
但是,如果我需要多个验证器(例如确认密码和确认电子邮件),则此解决方案将不起作用(或者如果其中一个不合适,则显示两条错误消息。如果您有建议,请不要犹豫。
下面是我为此使用的代码:
模板:
<p th:if="${#fields.hasErrors('username')}"th:errors="*{username}"></p>
<!-- works just fine -->
<p th:if="${#fields.hasErrors('*')}" th:errors="*{*}"></p>
<!-- works and displays all errors (for every field with an error,
including my custom validator) -->
<p th:if="${#fields.hasErrors('confirmPassword')}" th:errors="*{*}"></p>
<!-- does not work -->
<p th:if="${#fields.hasErrors('*')}" th:errors="*{confirmPassword}"></p>
<!-- does not work -->
验证器实现:
public class PasswordsEqualConstraintValidator implements
ConstraintValidator<PasswordsEqualConstraint, Object> {
@Override
public void initialize(PasswordsEqualConstraint arg0) {
}
@Override
public boolean isValid(Object candidate, ConstraintValidatorContext arg1) {
User user = (User) candidate;
return user.getPassword().equals(user.getConfirmPassword());
}
}
验证器接口:
@Target({ ElementType.TYPE })
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Constraint(validatedBy = PasswordsEqualConstraintValidator.class)
public @interface PasswordsEqualConstraint {
String message();
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
}
用户.java:
@PasswordsEqualConstraint(message = "passwords are not equal")
public class User implements java.io.Serializable {
...
@Size(min=2, max=40)
private String username;
...
private String confirmPassword;
...
控制器:
@RequestMapping(value = "/signup", method = RequestMethod.POST)
public String signup(@Valid User user, BindingResult bindingResult) {
if (bindingResult.hasErrors()) {
return "signup";
}
... do db stuff .. return "success";
}