@JsonTypeInfo visible=true serialises the field twice

Spun off from #250.

The below code will add a name field twice into the serialised JSON:

@JsonTypeInfo(use = JsonTypeInfo.Id.NAME, property = "name", visible = true)
public static abstract class Fruit {
    // @JsonIgnore
    public abstract String getName();
}

Adding in the @JsonIgnore is a workaround but I cannot imagine a circumstance where I would want that behaviour. This ticket is requesting a “visible” property be ignored by default during serialisation.

[cowtowncoder]

Oh. How quickly do I forget features I add. The REAL answer is that there is specific annotation – @JsonTypeId – to be used to indicate property that gives type id value. Its name may be same as specified by propertyName, but need not be; similarly, this id may be used with any inclusion methods (as-wrapper-array, as-wrapper-object, external-property).

[cowtowncoder]

Ok, so the current idea (wrt existing code) is that instead of @JsonIgnore, you should use @JsonTypeId. Whether you want visible=true or not depends on what you are trying to achieve: it is only needed if you have a matching setter. Setting of visible does not actually come into play here; rather it is just missing linkage between type id (which happens to be marked to be added as ‘name’) and regular property.

Still… it seems odd to add duplicate entries regardless. Question then becomes: which mechanism should be used for figuring out type id to use? If @JsonTypeId is used, answer seems clear: use the property (via getter or field access). Without it, it seems logical that type id should be generated instead.

I will try to see how to do such supression. Please let me know if I misunderstood anything from above.