响应中的Spring rest api filter字段

Question

我正在使用spring rest api 4.x. 我们需要根据请求参数过滤响应中的字段.

我的用户对象:

private class UserResource {
   private String userLastName;
   private String userFirstName;
   private String email;
   private String streetAddress;
}

E.g. URL:  curl -i http://hostname:port/api/v1/users?fields=firstName,lastName. 

在这种情况下,我只需要返回请求参数"fields"中的字段.JSON输出应仅包含firstName,lastName.

有几种方法可以根据对象过滤Jackson中的字段.在我的情况下,我需要通过将字段列表传递给Jackson序列化程序来动态过滤.

请分享一些想法.

Answer 1

谢谢阿里.这是一个很大的帮助.让我今天实施它.我会发布结果

@JsonFilter("blah.my.UserEntity")
public class UserEntity implements Serializable {
//fields goes here
}

@RequestMapping(value = "/users", method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_VALUE)
public MappingJacksonValue getUsers(@RequestParam MultiValueMap<String, String> params) {
//Build pageable here
Page<UserEntity> users = userService.findAll(pageable);

    MappingJacksonValue mappingJacksonValue = new MappingJacksonValue(users);
    FilterProvider filters = new SimpleFilterProvider()
                .addFilter("blah.my.UserEntity", SimpleBeanPropertyFilter
                        .filterOutAllExcept("userFirstName"));
    mappingJacksonValue.setFilters(filters);
    return mappingJacksonValue;
}

Answer 2

使用 aResponseBodyAdvice可以在响应写入 HTTP 响应之前更改响应。在beforeBodyWrite(...)方法中，您可以访问当前的值ServerHttpRequest，您可以读取该fields值。您的身体建议如下：

@ControllerAdvice
public class MyResponseBodyAdvisor implements ResponseBodyAdvice<UserResource> {
    @Override
    public boolean supports(MethodParameter returnType, Class<? extends HttpMessageConverter<?>> converterType) {
        return returnType.getParameterType().equals(UserResource.class);
    }

    @Override
    public UserResource beforeBodyWrite(UserResource body, MethodParameter returnType, MediaType selectedContentType, Class<? extends HttpMessageConverter<?>> selectedConverterType, ServerHttpRequest request, ServerHttpResponse response) {
        String fields = ((ServletServerHttpRequest) request).getServletRequest().getParameter("fields");
        // body.set...(null) for each field not in fields

        return body;
    }
}