Creates a TextField which only accepts digits and adds hypen after 3 and 6 digit.

PhoneNumberTextFieldSample.java

import javafx.application.Application;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.TextField;
import javafx.scene.control.TextFormatter;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;
import javafx.util.StringConverter;

public class PhoneNumberTextFieldSample extends Application {

    public void start(Stage stage) {

        final TextField textField = new TextField();
        final StringConverter<String> stringConverter = new StringConverter<>() {
            @Override
            public String toString(String object) {
                if (object.length() > 6) {
                    return object.substring(0, 3) + "-" + object.substring(3, 6) + "-"  + object.substring(6);
                } else if (object.length() > 3) {
                    return object.substring(0, 3) + "-" + object.substring(3);
                }
                return object;
            }

            @Override
            public String fromString(String string) {
                return string == null ? null : string.replace("-", "");
            }
        };
        textField.setTextFormatter(new TextFormatter<>(stringConverter, "", change -> {
            if (change.getText().chars().allMatch(Character::isDigit)) {
                return change;
            }
            return null;
        }));

        VBox root = new VBox(30, textField);
        root.setAlignment(Pos.CENTER);
        Scene scene = new Scene(root, 640, 480);
        stage.setScene(scene);
        stage.show();
    }

   public static void main(String[] args) {
        launch(args);
    }
}