Question

我想在API使用对象之前在dropwizard中使用@Valid。但是，对象的所有属性都没有得到验证，因为它似乎没有发生验证？我是否在添加配置以启用它时遗漏了一些内容？

仅供参考：我们已经实现了自己的消息体阅读器，它从javax.ws.rs.ext.MessageBodyReader扩展，用于将JSON映射到对象。

Answer 1

您需要在MessageBodyReader中存储javax.validation.Validator对象，并使用它来验证@Valid方法中使用readFrom()注释的类。这就是Dropwizard的杰克逊提供商所做的事情。

所以代码看起来像这样：

private static final Class<?>[] DEFAULT_GROUP_ARRAY = new Class<?>[]{ Default.class };
private final XmlMapper mapper;
private final Validator validator;

public MyMessageBodyReader(XmlMapper mapper, Validator validator) {
    this.validator = validator;
    this.mapper = mapper;
    setMapper(mapper);
}

@Override
public Object readFrom(Class<Object> type,
                       Type genericType,
                       Annotation[] annotations,
                       MediaType mediaType,
                       MultivaluedMap<String, String> httpHeaders,
                       InputStream entityStream) throws IOException {
    return validate(annotations, super.readFrom(type,
            genericType,
            annotations,
            mediaType,
            httpHeaders,
            entityStream));
}

private Object validate(Annotation[] annotations, Object value) {
    final Class<?>[] classes = findValidationGroups(annotations);

    if (classes != null) {
        final Set<ConstraintViolation<Object>> violations = validator.validate(value, classes);
        if (!violations.isEmpty()) {
            throw new ConstraintViolationException("The request entity had the following errors:",
                    ConstraintViolations.copyOf(violations));
        }
    }

    return value;
}

private Class<?>[] findValidationGroups(Annotation[] annotations) {
    for (Annotation annotation : annotations) {
        if (annotation.annotationType() == Valid.class) {
            return DEFAULT_GROUP_ARRAY;
        } else if (annotation.annotationType() == Validated.class) {
            return  ((Validated) annotation).value();
        }
    }
    return null;
}

我有一个示例here，我在其中编写了一个带有验证支持的自定义XML Jackson Reader + Writer。

dropwizard API资源中的@Valid

1 个答案: