JavaFX, text won't display in TextArea - javafx

Question

I have the majority of the program done, the only problem is getting the numbers to display in the TextArea. Write a program that lets the user enter numbers from a graphical user interface and displays them in a text area. Use a LinkedList to store the numbers. Don't duplicate numbers. Add sort, shuffle, reverse to sort the list.
package storedInLinkedList;
import java.util.Collections;
import java.util.LinkedList;
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.geometry.Orientation;
import javafx.geometry.Pos;
import javafx.scene.layout.HBox;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;
import javafx.scene.control.Label;
import javafx.scene.control.TextArea;
import javafx.scene.control.TextField;
import javafx.scene.layout.BorderPane;
import javafx.scene.control.ScrollPane;
public class StoredInLinkedList extends Application{
TextField txt = new TextField();
TextArea tArea = new TextArea();
Label message = new Label("Enter a Number: ");
Button sort = new Button("Sort");
Button shuffle = new Button("Shuffle");
Button reverse = new Button("Reverse");
private LinkedList<Integer> list = new LinkedList<>();
#Override
public void start(Stage primaryStage){
BorderPane bPane = new BorderPane();
txt.setAlignment(Pos.TOP_RIGHT);
bPane.setCenter(txt);
bPane.setBottom(tArea);
HBox hBox = new HBox(message, txt);
bPane.setTop(hBox);
HBox buttons = new HBox(10);
buttons.getChildren().addAll(sort, shuffle, reverse);
bPane.setBottom(buttons);
buttons.setAlignment(Pos.CENTER);
VBox vBox = new VBox();
vBox.getChildren().addAll(hBox, tArea, buttons);
bPane.setCenter(new ScrollPane(tArea));
Scene scene = new Scene(vBox, 300,250);
primaryStage.setTitle("20.2_DSemmes");
primaryStage.setScene(scene);
primaryStage.show();
txt.setOnAction(e -> {
if(! list.contains(new Integer(txt.getText()))){
tArea.appendText(txt.getText() + " ");
list.add(new Integer(txt.getText()));
}//end if
});//end action
sort.setOnAction(e -> {
Collections.sort(list);
display();
});//end action
shuffle.setOnAction(e -> {
Collections.shuffle(list);
display();
});//end action
reverse.setOnAction(e -> {
Collections.reverse(list);
display();
});//end action
}//end stage
private void display() {
for (Integer i: list){
tArea.setText(null);
tArea.appendText(i + " ");
}//end for
}//end display
public static void main(String[] args) {
// TODO Auto-generated method stub
launch(args);
}//end main
}//end class

Answer 1

Put the textarea clearing code outside of for loop. Otherwise you are clearing the previously appended text, so textarea having only the last element of list:
private void display() {
tArea.setText(""); // clear text area
for (Integer i: list){
tArea.appendText(i + " ");
}//end for
}/