gwt-jackson: Failing to instantiate interface Type

So I have a situation coming from GWT RPC serialization. GWT allowed you to provide an interface type as a return type and then you return an object that implements that interface. It appears gwt-jackson doesn’t offer this kind of deserialization?

I have an interface called ProcessPageData which has 2 implementors:

OpenIncidentData
InvestigationData

Unable to deserialize response. An unexpected error occurred.
Cannot instantiate the type nz.co.doltech.ims.shared.core.ProcessPageData`

Depending on the process that is being loaded it returns the appropriate data in the form of the class. This worked fine previously and I would love to know how this could be done with jackson.

Cheers! (Also, sorry I don’t know where else to post questions that I have 😄)

About this issue

Original URL
State: closed
Created 10 years ago
Comments: 18 (9 by maintainers)

Most upvoted comments

Your fields are private and your constructor isn’t annotated with @JsonCreator nor the parameters with @JsonProperty. So it means, gwt-jackson uses the default constructor (even if private) and it does not find any property because there is no setter or accessible property (getters does not count in deserialization).

If you want to keep your object without setter, you can

add @JsonProperty to your fields. gwt-jackson will still use the private constructor and set the private fields with jsni.
add @JsonCreator to your constructor and @JsonProperty to all of the parameters. gwt-jckson will then use this constructor.
a third option is to change the detection of your fields with @JsonAutoDetect and put fieldVisibility to ANY and gwt-jackson will do the same as in solution 1.

nmorel on Sep 16, 2014