Morse to text and text to morse - JavaFX

Controller.java

import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.scene.control.TextArea;
import javafx.scene.input.KeyEvent;

public class Controller {

    @FXML
    private TextArea textInput;

    @FXML
    private TextArea morseOutput;

    MorseCodeTranslator morseCodeTranslator = new MorseCodeTranslator();

    boolean morseToText = false;

    @FXML
    void updateMorseCode(KeyEvent event) {
        if(morseToText){
            morseOutput.setText(morseCodeTranslator.translateToText(textInput.getText()));
        }else {
            morseOutput.setText(morseCodeTranslator.translateToMorse(textInput.getText()));
        }
    }

    @FXML
    void switchStyle(ActionEvent event) {
        morseToText = !morseToText;
    }

}

Main.java

import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;

public class Main extends Application {

    @Override
    public void start(Stage primaryStage) throws Exception{
        Parent root = FXMLLoader.load(getClass().getResource("sample.fxml"));
        primaryStage.setTitle("Hello World");
        primaryStage.setScene(new Scene(root));
        primaryStage.show();
    }

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

MorseCodeTranslator.java

import java.util.HashMap;
import java.util.Map;

public class MorseCodeTranslator {

    Map<Character, String> morseToTextMapping = new HashMap<Character, String>();
    Map<String, Character> textToMorseMapping = new HashMap<String, Character>();

    char[] letter = { 'a', 'b', 'c', 'd', 'e', 'f',
            'g', 'h', 'i', 'j', 'k', 'l',
            'm', 'n', 'o', 'p', 'q', 'r',
            's', 't', 'u', 'v', 'w', 'x',
            'y', 'z', '1', '2', '3', '4',
            '5', '6', '7', '8', '9', '0', ' ' };

    String[] morse = { ".-", "-...", "-.-.", "-..", ".", "..-.", "--.", "....", "..",
            ".---", "-.-", ".-..", "--", "-.", "---", ".---.", "--.-", ".-.",
            "...", "-", "..-", "...-", ".--", "-..-", "-.--", "--..", ".----",
            "..---", "...--", "....-", ".....", "-....", "--...", "---..", "----.",
            "-----", "/" };

    public MorseCodeTranslator() {
        setupMap();
    }

    private void setupMap(){
        for (int i = 0; i < letter.length; i++) {
            morseToTextMapping.put(letter[i], morse[i]);
            textToMorseMapping.put(morse[i], letter[i]);
        }
    }

    public String translateToMorse(String text){
        char[] characters = text.toCharArray();
        StringBuilder morseString = new StringBuilder();

        for (char character : characters) {
            morseString.append(morseToTextMapping.get(character)).append(" ");
        }
        return String.valueOf(morseString);
    }

    public String translateToText(String morse){
        String[] morseArray = morse.split(" ");

        StringBuilder morseString = new StringBuilder();

        for (String morsePart : morseArray) {
            morseString.append(textToMorseMapping.get(morsePart));
        }
        return String.valueOf(morseString);
    }
}

sample.fxml

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.scene.control.Button?>
<?import javafx.scene.control.TextArea?>
<?import javafx.scene.layout.AnchorPane?>
<?import javafx.scene.text.Font?>
<?import javafx.scene.text.Text?>

<AnchorPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="400.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/15.0.1" xmlns:fx="http://javafx.com/fxml/1" fx:controller="sample.Controller">
   <children>
      <TextArea fx:id="textInput" layoutX="82.0" layoutY="64.0" onKeyTyped="#updateMorseCode" prefHeight="146.0" prefWidth="437.0">
         <font>
            <Font size="24.0" />
         </font>
      </TextArea>
      <TextArea fx:id="morseOutput" editable="false" layoutX="82.0" layoutY="226.0" prefHeight="146.0" prefWidth="437.0">
         <font>
            <Font size="24.0" />
         </font>
      </TextArea>
      <Text layoutX="175.0" layoutY="35.0" strokeType="OUTSIDE" strokeWidth="0.0" text="Morse Code Translator">
         <font>
            <Font size="25.0" />
         </font>
      </Text>
      <Button layoutX="519.0" layoutY="25.0" mnemonicParsing="false" onAction="#switchStyle" text="Switch" />
   </children>
</AnchorPane>