CODEWITHSUNDEEP
javajsonjackson
EJay
EJay

Reputation: 1159

Can the property @JSONIgnore be set on a per call basis?

I am working on a site that uses promo codes to potentially provide users free memberships to the site. The level that a member signs up at is an attribute of a promo code object and stored in the database as an int, either 1 or 2. However, the only time the member level attribute is relevant to the UI of the site is for a landing page associated with a specific promo code. So for that case, I don't want the member level to be ignored by JSON. After a user returns to the site and has a promo code object associated with their account, we no longer care about their member level so I would like the member level attribute to be ignored by JSON.

So my question is this, is it possible to set an object's attribute to @JSONIgnore on a per access basis, or can an attribute only be ignored or not ignored? In other words is there a method like object.getAttribute().setAttributeJSONIgnore(true | false)?

Upvotes: 9

Views: 21862

Answers (2)

Walt Moorhouse
Walt Moorhouse

Reputation: 71

I've done something similar with JSONViews (http://wiki.fasterxml.com/JacksonJsonViews).

You'd create a Base View and then extend it with a PromoPage View. In the object you're serializing, you'd add the annotation to each property. So the ones you want to appear every time would be 

@JsonView(Views.Base.class) 
String name;

The properties you only wanted to show on those certain Promo Pages would be something like

@JsonView(Views.PromoPage.class) 
Integer memberLevel;

Then if you have different JAX-RS methods for getting the promopages than the other landing page, you can annotate the methods with the appropriate View like so

  @JsonView(Views.Base.class)
  @GET
  @Produces(MediaType.APPLICATION_JSON )
  public Object getNormalLandingPageInfo() {
    ...
  }

  @JsonView(Views.PromoPage.class)
  @GET
  @Produces(MediaType.APPLICATION_JSON )
  public Object getPromoLandingPageInfo() {
    ...
  }

If you don't, in your logic, you can do whatever you want to determine when to show the PromoPage View, then do something like this

if (showPromoPage)
    objectMapper.writeValueUsingView(out, object, Views.PromoPage.class);
else
    objectMapper.writeValueUsingView(out, object, Views.Base.class);

Upvotes: 3

StaxMan
StaxMan

Reputation: 116522

No. Annotation-based approaches are static, since although you could use custom AnnotationIntrospector, resulting JsonSerializer instances are reused since their construction is costly.

But there are ways to filter out properties, check out "Filtering Properties" article, for example.

Upvotes: 7

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