Use annotation for excluding specific fields from serialization

Question

I'm trying to learn Gson and I'm struggling with field exclusion. Here are my classes

public class Student {    
  private Long                id;
  private String              firstName        = "Philip";
  private String              middleName       = "J.";
  private String              initials         = "P.F";
  private String              lastName         = "Fry";
  private Country             country;
  private Country             countryOfBirth;
}

public class Country {    
  private Long                id;
  private String              name;
  private Object              other;
}

I can use the GsonBuilder and add an ExclusionStrategy for a field name like firstName or countrybut I can't seem to manage to exclude properties of certain fields like country.name.

Using the method public boolean shouldSkipField(FieldAttributes fa), FieldAttributes doesn't contain enough information to match the field with a filter like country.name.

I would appreciate any help with a solution for this problem.

P.S: I want to avoid annotations since I want to improve on this and use RegEx to filter fields out.

Thank you

Answer 1

Simply mark the desired fields with the @Expose annotation, such as:

@Expose private Long id;

Leave out any fields that you do not want to serialize. Then just create your Gson object this way:

Gson gson = new GsonBuilder().excludeFieldsWithoutExposeAnnotation().create();