JavaFX ListView set selection model to multiple selection

import javafx.application.Application;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.ComboBox;
import javafx.scene.control.ContentDisplay;
import javafx.scene.control.Label;
import javafx.scene.control.ListView;
import javafx.scene.control.ScrollPane;
import javafx.scene.control.SelectionMode;
import javafx.scene.layout.BorderPane;
import javafx.stage.Stage;

public class Main extends Application {
   protected ObservableList<String> items = FXCollections.observableArrayList("China", "Japan", "Korea", "India",
         "Malaysia", "Vitnam");
   protected ListView<String> lv = new ListView<>(items);
   protected ComboBox<String> cbo = new ComboBox<>();
   protected Label lblSelectedItems = new Label("Selected items are ");

   @Override//from   w w  w. j  a v  a 2 s .co  m
   public void start(Stage primaryStage) {
      // Set combo box properties
      cbo.getItems().addAll("SINGLE", "MULTIPLE");
      cbo.setValue("SINGLE");

      // Create a label and set its content display
      Label lblSelectionMode = new Label("Choose Selection Mode:", cbo);
      lblSelectionMode.setContentDisplay(ContentDisplay.RIGHT);

      // Set defaut list view as single
      lv.getSelectionModel().setSelectionMode(SelectionMode.SINGLE);

      // Create and register the handlers
      cbo.setOnAction(e -> {
         setMode();
         setText();
      });

      lv.getSelectionModel().selectedItemProperty().addListener(ov -> {
         setMode();
         setText();
      });

      // Place nodes in the pane
      BorderPane pane = new BorderPane();
      pane.setTop(lblSelectionMode);
      pane.setCenter(new ScrollPane(lv));
      pane.setBottom(lblSelectedItems);
      pane.setAlignment(lblSelectionMode, Pos.CENTER);

      // Create a scene and place it in the stage
      Scene scene = new Scene(pane, 268, 196);
      primaryStage.setTitle("java2s.com");
      primaryStage.setScene(scene);
      primaryStage.show();
   }

   /** Set list view selection mode */
   private void setMode() {
      if (cbo.getValue().equals("SINGLE"))
         lv.getSelectionModel().setSelectionMode(SelectionMode.SINGLE);
      else
         lv.getSelectionModel().setSelectionMode(SelectionMode.MULTIPLE);
   }

   /** Set label text to list view selected items */
   private void setText() {
      String items = "Selected items are ";
      for (String i : lv.getSelectionModel().getSelectedItems())
         items += i + " ";
      lblSelectedItems.setText(items);
   }
}