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(bind)结果添加 FieldError。不过,我的自定义 validator 会传递一个 ObjectError 。我不知道如何让 Thymeleaf 显示我的自定义错误(显然已经通过了,因为 th:errors="*{*}"
显示了它)。
非常感谢任何帮助。
更新: 我现在可以通过
显示错误消息<p th:if="${#fields.hasErrors('${user}')}" th:errors="${user}"></p>
但是,如果我需要多个 validator (例如确认密码和确认电子邮件),则此解决方案将不起作用(或者如果其中一个不合适,则显示两条错误消息。如果您有建议,请不要犹豫。
下面是我为此使用的代码:
模板:
<p th:if="${#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 -->
validator 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());
}
}
validator 接口(interface):
@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;
...
Controller :
@RequestMapping(value = "/signup", method = RequestMethod.POST)
public String signup(@Valid User user, BindingResult bindingResult) {
if (bindingResult.hasErrors()) {
return "signup";
}
... do db stuff .. return "success";
}
最佳答案
这可能是因为您的 @PasswordsEqualConstraint 被分配给整个 bean(类型)而不是字段“confirmPassword”。要将可能的约束违规添加到具体字段,您可以按照下面的示例进行操作。
FieldMatch 比较两个字段,如果它们不相等,则将验证错误分配给第二个字段。
顺便说一句。对于您正在做的事情来说,这是更通用的解决方案。例如,对于密码,您可以使用它,例如@FieldMatch(first = "password", second = "confirmPassword", message = "Passowords are not equal.")
validator :
public class FieldMatchValidator implements ConstraintValidator<FieldMatch, Object> {
private String firstFieldName;
private String secondFieldName;
@Override
public void initialize(final FieldMatch constraintAnnotation) {
firstFieldName = constraintAnnotation.first();
secondFieldName = constraintAnnotation.second();
}
@Override
public boolean isValid(final Object value, final ConstraintValidatorContext context) {
try {
final Object firstObj = BeanUtils.getProperty(value, firstFieldName);
final Object secondObj = BeanUtils.getProperty(value, secondFieldName);
boolean isValid = firstObj == null && secondObj == null || firstObj != null && firstObj.equals(secondObj);
if (!isValid) {
context.disableDefaultConstraintViolation();
context.buildConstraintViolationWithTemplate(context.getDefaultConstraintMessageTemplate()).addNode(secondFieldName).addConstraintViolation();
}
return isValid;
}
catch (final Exception ignore) {
// ignore
}
return true;
}
}
关于java - Spring + Thymeleaf 自定义验证展示,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/32611556/