myCode

========================================
Users.java
=================================================


public class Users {

    public String userEmail;
    public String userName;
    public String userPass;
   public String uuid;
    public String userAge;
    public String userNumber;
    public String userGender;

    public Users() {
    }

    public Users(String userEmail, String userName, String userPass,String uuid, String userAge, String userNumber, String userGender) {
        this.userEmail = userEmail;
        this.userName = userName;
        this.userPass = userPass;
        this.uuid = uuid;
        this.userAge = userAge;
        this.userNumber = userNumber;
        this.userGender = userGender;
    }


    public void saveUser() {
        Users user = new Users(userEmail, userName, userPass,uuid,  userAge, userNumber, userGender);
        FirebaseDatabase database = FirebaseDatabase.getInstance();
        DatabaseReference myRef = database.getReference("Users");
        myRef.child(uuid).setValue(user);
    }

}


=======================================================================
mainActivity.java
===========================================================================


public class MainActivity extends AppCompatActivity {


        FirebaseAuth auth;
        ProgressBar progressBar;
        Button btnLogin;
        Button btnRegister;
        Context context;
        EditText txtUserEmail;
        EditText txtUserPassword;
        EditText txtEmail, txtName, txtPassword, txtPassword2, txtAge, txtNumber;
        RadioButton radio0, radio1;
        final List<Users> myData = new ArrayList<>();


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        setPointer();
        context = this;
        //for checking, avoiding user login (test purpose only)
       // startActivity(new Intent(this,Welcome.class));
    }

    private void setPointer() {
        this.context = this;
        txtUserEmail = (EditText) findViewById(R.id.txtUserEmail);
        txtUserPassword = (EditText) findViewById(R.id.txtUserPassword);
        btnLogin = (Button) findViewById(R.id.btnLogin);
        btnRegister = (Button) findViewById(R.id.btnRegister);
        auth = FirebaseAuth.getInstance();
        progressBar = (ProgressBar) findViewById(R.id.progressBar);


        btnLogin.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                login();
            }
        });

        btnRegister.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                register();
            }
        });
    }



  private String getUUID() {
       //create a unique UUID
       UUID idOne = UUID.randomUUID();
        //returning the UUID
      return idOne.toString();
    }

    public void createUser(View view) {
        setUserData();
    }

    private void setUserData() {

        //getting the info from the activity
        final String userEmail = txtEmail.getText().toString();
        final String userName = txtName.getText().toString();
        final String userPass = txtPassword.getText().toString();
        final String userAge = txtAge.getText().toString();
        final String userNumber = txtNumber.getText().toString();
        final String userGender = radio0.isChecked() ? "Male" : "Female";


        //creating new instance of the project
        Users user = new Users(userEmail, userName, userPass,getUUID(),  userAge, userNumber, userGender);
        //calling inside method from the class to save the data
        user.saveUser();
        auth.createUserWithEmailAndPassword(userEmail, userPass)
                .addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
                    @Override
                    public void onComplete(@NonNull Task<AuthResult> task) {
                        //waitForDebugger();
                        Log.d("Register", "Authentication successful");
                        if (!task.isSuccessful()) {
                            Toast.makeText(context, "Authentication failed.",  Toast.LENGTH_SHORT).show();
                        }
                    }
                });
    }


    private void register() {
        android.app.AlertDialog.Builder builder = new android.app.AlertDialog.Builder(context);
        builder.setTitle(R.string.register);
        final View viewInflated = LayoutInflater.from(context).inflate(R.layout.rgs_new_rgs, null, true);

        txtEmail = (EditText) viewInflated.findViewById(R.id.txtEmail);
        txtName = (EditText) viewInflated.findViewById(R.id.txtName);
        txtPassword = (EditText) viewInflated.findViewById(R.id.txtPassword);
        txtPassword2 = (EditText) viewInflated.findViewById(R.id.txtPassword2);
        txtAge = (EditText) viewInflated.findViewById(R.id.txtAge);
        txtNumber = (EditText) viewInflated.findViewById(R.id.txtNumber);
        radio0 = (RadioButton) viewInflated.findViewById(R.id.radio0);
        radio1 = (RadioButton) viewInflated.findViewById(R.id.radio1);

        builder.setNegativeButton(R.string.cancel, new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialogInterface, int i) {
                dialogInterface.dismiss();
            }
        });

        builder.setPositiveButton(R.string.register, new DialogInterface.OnClickListener() {

            @Override
            public void onClick(DialogInterface dialogInterface, int i) {

                String Email = txtEmail.getText().toString();
                String Name = txtName.getText().toString();
                String Pass1 = txtPassword.getText().toString();
                String Pass2 = txtPassword2.getText().toString();
                String Age = txtAge.getText().toString();
                String Number = txtNumber.getText().toString();

                if (Email.equals("")) {
                    Toast.makeText(context, "please Enter Email", Toast.LENGTH_SHORT).show();
                    register();
                    return;
                }

                if (Name.equals("")) {
                    Toast.makeText(context, "please Enter Name", Toast.LENGTH_SHORT).show();
                    register();
                    return;
                }

                if (!Pass1.equals(Pass2)) {
                    Toast.makeText(context, R.string.errorSamepass, Toast.LENGTH_LONG).show();
                    register();
                    return;
                }

                if (Pass1.equals("")) {
                    Toast.makeText(context, "please Enter password", Toast.LENGTH_SHORT).show();
                    register();
                    return;
                }

                if (Age.equals("")) {
                    Toast.makeText(context, "please Enter Your Age", Toast.LENGTH_SHORT).show();
                    register();
                    return;
                }

                if (Number.equals("")) {
                    Toast.makeText(context, "please Enter Your Number", Toast.LENGTH_SHORT).show();
                    register();
                    return;
                }


                setUserData();
            }

        });

        builder.setView(viewInflated);
        builder.show();

    }


    private void login() {
        String email = txtUserEmail.getText().toString();
        final String password = txtUserPassword.getText().toString();

        if (TextUtils.isEmpty(email)) {
            Toast.makeText(getApplicationContext(), "Enter email address!", Toast.LENGTH_SHORT).show();
            return;
        }

        if (TextUtils.isEmpty(password)) {
            Toast.makeText(getApplicationContext(), "Enter password!", Toast.LENGTH_SHORT).show();
            return;
        }

        progressBar.setVisibility(View.VISIBLE);


        //authenticate user
        auth.signInWithEmailAndPassword(email, password)
                .addOnCompleteListener(MainActivity.this, new OnCompleteListener<AuthResult>() {
                    @Override
                    public void onComplete(@NonNull Task<AuthResult> task) {

                        progressBar.setVisibility(View.GONE);
                        if (!task.isSuccessful()) {


                                Toast.makeText(MainActivity.this, getString(R.string.auth_failed), Toast.LENGTH_LONG).show();
                            }
                        else {
                            Intent intent = new Intent(MainActivity.this, Welcome.class);
                            startActivity(intent);
                            finish();
                        }
                    }
                });

    }


        @Override
        protected void onResume() {
            super.onResume();
            progressBar.setVisibility(View.GONE);
    }
}