How to implement soft (logical) delete with MongoDB and Spring?

Question

I have Spring web app with MongoDB. Currently I always permanently delete data from database.

@Repository
public class SessionRepository extends CrudRepository implements SessionService {
  ...
  @Override
  public void insert(Session session) {
    saveRoom(session);
    getTemplate().insert(session);
  }

  @Override
  public void delete(Session session) {
    getTemplate().remove(session);
  }
  ...    
}

What would be a good way to change this into soft delete?

----------------- edit 1 -------------------

I understand the logic now what I should do, thanks Sarath Nair. But I am unsure how to implement this in Spring. I have a Session object:

@Document(collection = "session")
public class Session {

  @Id
  private String id;
  private Date startDate;
  private Date endDate;
//I just put this here
  private boolean deleted = false;

  public boolean isDeleted() {
    return deleted;
  }

  public void setDeleted(boolean deleted) {
    this.deleted = deleted;
  }

  ...
}

I want the field boolean isDeleted to be present in the database but I don't wan't to send that piece of information out with a web service. @Transient is no good because then the field won't show up in database nor in the HTTP response. Right now I am sending deleted: false in my HTTP response.

How should I edit my Session class?

Answer 1

Have an additional field called is_deleted in collection. Insert is_deleted as false for new documents. When you are deleting just update this value to true for that document. Whenever you need to read documents from collection, pass is_deleted : false for the collection.

Answer 2

Solution with "isDeleted" field will not work because @DbRef still retrieves the "isDeleted" records, I am playing around this problem too.

For your second question, you can use custom SpringHttpMessageConverters with GSON to hide "isDeleted" field.