android - 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, make sure these constructors are not stripped.

protected void onStart() {
        super.onStart();
        ref.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {
                //artistList.clear();
                for(DataSnapshot artistSnapshot : dataSnapshot.getChildren()){
                    Artist artist = artistSnapshot.getValue(Artist.class);
                    Toast.makeText(MainActivity.this, artist.getArtistName(), Toast.LENGTH_SHORT).show();

                }

            }

            @Override
            public void onCancelled(DatabaseError databaseError) {

            }
        });
    }

Artist.java

package com.rcpl.agni;

/**
 * Created by Dell-pc on 23-01-2018.
 */

public class Artist {
    String artistId;
    String artistName;
    String artistGenre;

    public Artist(String artistId, String artistName, String artistGenre) {
        this.artistId = artistId;
        this.artistName = artistName;
        this.artistGenre = artistGenre;
    }

    public String getArtistId() {
        return artistId;
    }

    public String getArtistName() {
        return artistName;
    }

    public String getArtistGenre() {
        return artistGenre;
    }
}

Answer 1

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