java在序列化时向JSON添加自定义元素

Question

我有几个JPA实体，比如

public class Person implements Serializable
{
  @Id
  private long                      id;

  @OneToMany(mappedBy = "Person", fetch = FetchType.LAZY)
  private List<Adresse>             adressen;

  @ManyToOne
  private Gender                    gender;
  
  [...]
}

还有更多。我现在的任务是将这些实体打印成JSON
目前我使用的是：

public String createJSONFromObject(Object obj)
{
 Gson gson = new GsonBuilder().setPrettyPrinting().setExclusionStrategies(new ExcludeProxiedFields()).create();
 String json = gson.toJson(obj);
 return json;
}

与

public class ExcludeProxiedFields implements ExclusionStrategy{
    
 @Override
 public boolean shouldSkipField(FieldAttributes fa) {
  return fa.getAnnotation(ManyToOne.class) != null ||
     fa.getAnnotation(OneToOne.class) != null ||
     fa.getAnnotation(ManyToMany.class) != null  ||
     fa.getAnnotation(OneToMany.class) != null;
 }        
}

因为我在尝试序列化这些字段时出错

在排除字段时，是否有方法向JSON添加自定义字段？例如，我想包括外国表的ID

我是否排除了太多？有更清洁的解决方案吗