[FIXED] Filtering entity fields dynamically in Spring Data rest json Response

Issue

Hi I have a requirement to dynamically ignore entity fields in spring data rest response [I know they can be done in a static way by using @JsonIgnore annotation] ideally based on a spring security Role .The role part is still manageable but how to dynamically ignore fields in the json response is a challenge. After some analysis and the docs I think jackson is the way to go as spring data rest does provide jackson customization via jackson modules and mixins http://docs.spring.io/spring-data/rest/docs/current/reference/html/#customizing-sdr.custom-jackson-deserialization .

So I think in jackson api it could be done via @jsonFilter and then suppling the same when the ObjectMapper write the object [more details here http://www.cowtowncoder.com/blog/archives/2011/09/entry_461.html] .

But I am not sure how this could be wired up with Spring data rest (basically the part where I acan inject the filterprovider into spring data rest objectmapper).Let me know if anyone has tried this or someone from the Spring data team has insights .

Will post an answer myself If I am able to achieve the same.

UPDATE

So I figured out that the way to implement custom filtering is through the jackson BeanSerializerModifier .Got great help from @cowtowncoder on twitter .Also helpful reference or holy grails for filtering with jackson http://www.cowtowncoder.com/blog/archives/2011/02/entry_443.html

Solution

So yes finally I was able to solve this .The trick here is to use a custom BeanSerializerModifier and register it via a Custom Module [which is the custom hook available to customize spring data rest jackson serialization],something like

 setSerializerModifier( new CustomSerializerModifier()).build()));

now you can customize our BeanSerializerModifier by overriding the method changeProperties to apply your custom filter ,which basically includes and excludes BeanPropertyWriter based on your logic .sample below

List<BeanPropertyWriter> included = Lists.newArrayList();
    for (BeanPropertyWriter property : beanProperties)
        if (!filter.contains(property.getName()))
            included.add(property);

this way you can include any logic per class or otherwise and filter properties form response in a custom manner.Hope It Helps

Also have updated my code on github do look at https://github.com/gauravbrills/SpringPlayground

Answered By - Gaurav Rawat