Detect that EditText's Input is Number and do not allow the user type other sort of characters

Hi there i was developing an app then i got into how can my app detect the input of edit text. For example after putting something in edittext , i want only Digit inputs not characters.

public class percentInputActivity extends AppCompatActivity {
    EditText correctInputText = (EditText) findViewById(R.id.inputCorrect);
    Button calButton = (Button) findViewById(R.id.calButton);
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_percent_input);



    }}