public class MainActivity extends AppCompatActivity {

private FirebaseAuth mAuth;
private DatabaseReference userRef;
EditText nameEditText;
EditText passEditText;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    nameEditText = (EditText) findViewById(R.id.nameEditText);
    passEditText = (EditText) findViewById(R.id.passEditText);

    mAuth = FirebaseAuth.getInstance();
    //        signInAnonymously();
            mAuth.signInAnonymously().addOnFailureListener(new OnFailureListener() {
                @Override
                public void onFailure(@NonNull Exception e) {

                }

                public void onFailure(Throwable throwable) {
                    throw new RuntimeException(throwable);
                }
            });
}
public void createUser(View view){

    Random random = new Random();



    userRef = FirebaseDatabase.getInstance().getReference();



    String userN = String.valueOf(nameEditText.getText());
    String pass = String.valueOf(passEditText.getText());


    UserDetails newUser = new UserDetails(userN,pass);

    userRef.child("Users").child(Integer.toString(random.nextInt(100))).setValue(newUser);


}

public String userName;
public String password;

public UserDetails(){

}

public UserDetails(String userName, String userPass){

    this.userName = userName;
    this.password = userPass;
    Log.i("Check", this.userName);

}

public String getUserName() {
    return userName;
}

public String getPassword() {
    return password;
}