com.google.firebase.database.DatabaseException

Question

When I start the activity, it is showing the error:

Class com.rcpl.agni.Artist does not define a no-argument constructor.If you are using ProGuard,

Answer 1

To solve this, you just need to add the public no-argument constructor to your Artist class.

public Artist() {}

Remember, when the Firebase Realtime Database SDK deserializes objects coming from the database, it requires that any objects to a have a public no-argument constructor. This is needed to instantiate that particular object. All the fields within the object are set by using public setter methods or direct access to public members.

If you don't use a public no-arg constructor, the SDK doesn't know how to create an instance of the class. Most serialization libraries will have the same requirement.