Data to Model type erasure problem, data to model type

Data to Model type erasure problem, data to model type

If Class B inherits Class A and Class B is included in the Data, convert Class B to Data and store the Data. Since the type declared by the Model is A, the transferred data is also A, so that part of the data is lost.

Alternatively, the data is stored in the model set, and the data is erased after it is saved and retrieved.

The reason is that when class objects are serialized and deserialized, many third-party libraries only take the type declared by the Model as the standard and do not handle the type erasure problem.

It is easy to solve the problem. You only need to save the actual class type. SimilarGsonWithTypeTokenObtain the actual type.

Take a note here to avoid this pitfall.