android login with php mysql

Question

JI'm working on android login with php mysql and the login function takes forever. I'm trying to get to the bottom of this only im unsure whats causing it.

below : main activity  and connexion 

public class MainActivity extends AppCompatActivity {

    private EditText phonenumber, password;
    private com.rey.material.widget.CheckBox checkboxRememberMe;

    private DatabaseReference table_user;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


        phonenumber = findViewById(R.id.username1);
        password = findViewById(R.id.password1);
        Button buttonLogin = findViewById(R.id.buttonSignIn);

        checkboxRememberMe = findViewById(R.id.checkbox1);
        ImageView topIcon = findViewById(R.id.icon1);
        TextView forgotPassword = findViewById(R.id.forgotpassword1);

       // 2000ms = 2secs which is the delay for the splash screen
       // handler.postDelayed(runnable, 2000);

        //initialize Paper
        Paper.init(this);

        // check remember user
        String phone = Paper.book().read(Common.USER_KEY);
        String pass = Paper.book().read(Common.PASS_KEY);

        if (phone != null && pass != null){
            if (!phone.isEmpty() && !pass.isEmpty()){
                login(phone, pass);
            }
        }

        // init Firebase
        table_user = FirebaseDatabase.getInstance().getReference("User");

        forgotPassword.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                Intent forgotLayout = new Intent(MainActivity.this, ForgotPassword.class);
                startActivity(forgotLayout);

            }

        });

        buttonLogin.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                // make sure the input fields are not empty
                if (phonenumber.getText().length() > 0 && password.getText().length() > 0) {

                    if (Common.isConnectedToInternet(getBaseContext())) {

                        //save username and password
                        if (checkboxRememberMe.isChecked()){
                            Paper.book().write(Common.USER_KEY, phonenumber.getText().toString());
                            Paper.book().write(Common.PASS_KEY, password.getText().toString());
                        }

                        // display a loading dialog
                        final ProgressDialog mDialog = new ProgressDialog(MainActivity.this);
                        mDialog.setMessage("Please wait...");
                        mDialog.show();

                        table_user.addListenerForSingleValueEvent(new ValueEventListener() {
                            @Override
                            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {

                                // check user exists in db
                                if (dataSnapshot.child(phonenumber.getText().toString()).exists()) {
                                    mDialog.dismiss();
                                    // get user info
                                    User user = dataSnapshot.child(phonenumber.getText().toString()).getValue(User.class);
                                    assert user != null;
                                    if (user.getPassword().equals(password.getText().toString())) {
                                        Toast.makeText(MainActivity.this, "Welcome", Toast.LENGTH_SHORT).show();

                                        Intent home = new Intent(MainActivity.this, Home.class);
                                        Common.currentUser = user;
                                        startActivity(home);
                                        finish();
                                    } else {
                                        Toast.makeText(MainActivity.this, "Please try again", Toast.LENGTH_SHORT).show();
                                    }
                                } else {
                                    mDialog.dismiss();
                                    Toast.makeText(MainActivity.this, "User doesn't exist", Toast.LENGTH_SHORT).show();
                                }
                            }

                            @Override
                            public void onCancelled(@NonNull DatabaseError databaseError) {

                            }
                        });
                    }else {
                        Toast.makeText(MainActivity.this, "Please make sure you're connected to the Internet", Toast.LENGTH_SHORT).show();
                    }

                }else {
                    Toast.makeText(MainActivity.this, "Username/Password can not be empty", Toast.LENGTH_SHORT).show();
                }

            }
        });


    }

    private void login(final String phone, final String pass) {
        // init Firebase
        table_user = FirebaseDatabase.getInstance().getReference("User");

        if (Common.isConnectedToInternet(getBaseContext())) {

            // display a loading dialog
            final ProgressDialog mDialog = new ProgressDialog(MainActivity.this);
            mDialog.setMessage("Please wait...");
            mDialog.show();

            table_user.addListenerForSingleValueEvent(new ValueEventListener() {
                @Override
                public void onDataChange(@NonNull DataSnapshot dataSnapshot) {

                    // check user exists in db
                    if (dataSnapshot.child(phone).exists()) {
                        mDialog.dismiss();
                        // get user info
                        User user = dataSnapshot.child(phone).getValue(User.class);

                        assert user != null;
                        if (user.getPassword().equals(pass)) {
                            Toast.makeText(MainActivity.this, "Welcome", Toast.LENGTH_SHORT).show();

                            Intent home = new Intent(MainActivity.this, Home.class);
                            Common.currentUser = user;
                            startActivity(home);
                            finish();
                        } else {
                            Toast.makeText(MainActivity.this, "Please try again", Toast.LENGTH_SHORT).show();
                        }
                    } else {
                        mDialog.dismiss();
                        Toast.makeText(MainActivity.this, "User doesnt exist", Toast.LENGTH_SHORT).show();
                    }
                }

                @Override
                public void onCancelled(@NonNull DatabaseError databaseError) {

                }
            });
        }else {
            Toast.makeText(MainActivity.this, "Please make sure you're connected to the Internet", Toast.LENGTH_SHORT).show();
        }

public class Common {
    public static User currentUser;

    public static final String USER_KEY = "User";
    public static final String PASS_KEY = "Password";

    // for the mysql db
 public static final String URL_REQUEST = "10.0.2.2/gani/login.php";

    // check if Device is connected to internet or not.
    public static boolean isConnectedToInternet(Context context){
        ConnectivityManager connectivityManager = (ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);

        if (connectivityManager != null){
            NetworkInfo[] info = connectivityManager.getAllNetworkInfo();

            if (info != null){

                for (NetworkInfo anInfo : info) {

                    if (anInfo.isConnectedOrConnecting()) {
                        return true;
                    }
                }
            }
        }
        return false;
    }