Mapping json to Java pojo

Hello,
i have an issue using the following API : "GET /API/v3/survey-definitions/:surveyID/questions"
This API return a question list.
The "validation" field may vary from one question to another.
For exemple question :
Question Q1 is returned with "Validation": "None"
Question Q2 is returned with "Validation": { "Settings": { "ForceResponse": "OFF", "ForceResponseType": "ON", "Type": "None" }  }

How can i deserialize this in Java (using com.fasterxml.jackson.core) ?
Thank you.