JavaFX: TableView Print Selected Row item - javafx

Question

I currently have a tableview that displays a bunch of info on player stored on a database. What I'm trying to do, is simply print the first name of the name to console when its row is selected. Nothing is getting printed. I will post the entire code from table view to where I'm trying to print. I'm leaving out the function that loads players to the tableview as its unrelated
//Start Right Menu
TableView<TableDisplay> table = new TableView<>();
final ObservableList<TableDisplay> data =
FXCollections.observableArrayList();
TableColumn column1 = new TableColumn("Id");
column1.setMinWidth(100);
column1.setCellValueFactory(new PropertyValueFactory<>("id"));
TableColumn column2 = new TableColumn("First Name");
column2.setMinWidth(100);
column2.setCellValueFactory(new PropertyValueFactory<>("firstName"));
TableColumn column3 = new TableColumn("Last Name");
column3.setMinWidth(100);
column3.setCellValueFactory(new PropertyValueFactory<>("lastName"));
TableColumn column4 = new TableColumn("Birthdate");
column4.setMinWidth(100);
column4.setCellValueFactory(new PropertyValueFactory<>("birthdate"));
TableColumn column5 = new TableColumn("Nationality");
column5.setMinWidth(100);
column5.setCellValueFactory(new PropertyValueFactory<>("nationality"));
TableColumn column6 = new TableColumn("Height");
column6.setMinWidth(100);
column6.setCellValueFactory(new PropertyValueFactory<>("height"));
TableColumn column7 = new TableColumn("Position");
column7.setMinWidth(100);
column7.setCellValueFactory(new PropertyValueFactory<>("Position"));
TableColumn column8 = new TableColumn("Foot");
column8.setMinWidth(100);
column8.setCellValueFactory(new PropertyValueFactory<>("foot"));
TableColumn column9 = new TableColumn("Team Id");
column9.setMinWidth(100);
column9.setCellValueFactory(new PropertyValueFactory<>("teamId"));
table.getColumns().addAll(column1, column2, column3, column4, column5, column6, column7, column8, column9);
rightEditMenu.getChildren().addAll(table);
//End Right Menu
//Start Left Menu 2
This is where I'm trying to print but not working
TableDisplay person = table.getSelectionModel().getSelectedItem();
if(table.getSelectionModel().getSelectedItem() != null) {
System.out.println(person.getFirstName());
}

Answer 1

As I do not see a listener of any type in your code, I am assuming you do not have one.
It seems like you are trying to print the value of a selection before the Scene has even been loaded, which means no selection has been made by the user yet.
So add the following code when setting up your TableView:
// Add a listener to print the selected item to console when selected
table.getSelectionModel().selectedItemProperty().addListener((observableValue, oldValue, newValue) -> {
if (newValue != null) {
System.out.println("Selected Person: "
+ newValue.getId() + " | "
+ newValue.getFirstName() + " " + newValue.getLastName()
);
}
});
Now whenever a row is selected, this Listener is triggered and prints the values from newValue which represents the object stored in the selected row.
Since you did not provide an MCVE of your own, see the below example. You also do not declare what type of class your TableView and TableColumn objects are meant to display; this is a poor design and should be updated as in the below example.
import javafx.application.Application;
import javafx.beans.property.IntegerProperty;
import javafx.beans.property.SimpleIntegerProperty;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.cell.PropertyValueFactory;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;
public class Main extends Application {
public static void main(String[] args) {
launch(args);
}
#Override
public void start(Stage primaryStage) {
// Simple UI
VBox root = new VBox(10);
root.setAlignment(Pos.CENTER);
root.setPadding(new Insets(10));
// Setup the TableView and columns
TableView<Person> table = new TableView<>();
TableColumn<Person, Integer> colId = new TableColumn<>("ID");
colId.setMinWidth(100);
colId.setCellValueFactory(new PropertyValueFactory<>("id"));
TableColumn<Person, String> colFirstName = new TableColumn<>("First Name");
colFirstName.setMinWidth(100);
colFirstName.setCellValueFactory(new PropertyValueFactory<>("firstName"));
TableColumn<Person, String> colLastName = new TableColumn<>("Last Name");
colLastName.setMinWidth(100);
colLastName.setCellValueFactory(new PropertyValueFactory<>("lastName"));
// Add the columns to the TableView
table.getColumns().addAll(colId, colFirstName, colLastName);
// Add a listener to print the selected item to console when selected
table.getSelectionModel().selectedItemProperty().addListener((observableValue, oldValue, newValue) -> {
if (newValue != null) {
System.out.println("Selected Person: "
+ newValue.getId() + " | "
+ newValue.getFirstName() + " " + newValue.getLastName()
);
}
});
// Sample Data
ObservableList<Person> people = FXCollections.observableArrayList();
people.addAll(
new Person(1, "John", "Smith"),
new Person(2, "William", "Scott"),
new Person(4, "Susan", "Ryder")
);
table.setItems(people);
root.getChildren().add(table);
// Show the stage
primaryStage.setScene(new Scene(root));
primaryStage.setWidth(300);
primaryStage.setHeight(300);
primaryStage.show();
}
public static class Person {
private final IntegerProperty id = new SimpleIntegerProperty();
private final StringProperty firstName = new SimpleStringProperty();
private final StringProperty lastName = new SimpleStringProperty();
Person(int id, String firstName, String lastName) {
this.id.set(id);
this.firstName.set(firstName);
this.lastName.set(lastName);
}
public int getId() {
return id.get();
}
public IntegerProperty idProperty() {
return id;
}
public String getFirstName() {
return firstName.get();
}
public StringProperty firstNameProperty() {
return firstName;
}
public String getLastName() {
return lastName.get();
}
public StringProperty lastNameProperty() {
return lastName;
}
}
}