JavaFX TableView Context menu get the selected ID - javafx

Question

I have a TableView where I display data from my database. The TableView itself is not hard-coded on a specific table but it adds the columns and the data instead. I added Context menu, so when the user right clicks on an item, it deletes it. It works fine but I don't know how to get the ID which is the first column. Note that I don't want the selected index but the ID from the tableView (first column).
The questioned snippet:
removeMenuItem.setOnAction(event -> {
System.out.println(row.getItem()); // HERE
this.tableView.getItems().remove(row.getItem());
});
Basically, row.getItem() returns the record:
[2, Name, Stuff, Test Test, Category]
The question is how do I get the ID (in this case 2) or the name?
Full code:
package controllers;
import javafx.beans.binding.Bindings;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.value.ObservableValue;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.fxml.FXML;
import javafx.scene.control.*;
import javafx.util.Callback;
import java.sql.ResultSet;
import java.sql.SQLException;
public class TableController {
#FXML
private Label descriptionLabel;
#FXML
private TableView tableView;
public void setTableResultSet(String label, ResultSet resultSet) throws SQLException {
// Create context menu
createContextMenu();
// Set label text
descriptionLabel.setText(label);
// Resolve columns
ObservableList<ObservableList> data = resolveTableColumns(resultSet);
// Add records
addTableRecords(resultSet, data);
}
/**
* Create a context menu responsible for removing items.
*/
private void createContextMenu() {
tableView.setRowFactory(tableView -> {
final TableRow row = new TableRow();
final ContextMenu contextMenu = new ContextMenu();
final MenuItem removeMenuItem = new MenuItem("Remove");
removeMenuItem.setOnAction(event -> {
System.out.println(row.getItem()); // HERE
this.tableView.getItems().remove(row.getItem());
});
contextMenu.getItems().add(removeMenuItem);
// Set context menu on row, but use a binding to make it only show for non-empty rows:
row.contextMenuProperty().bind(
Bindings.when(row.emptyProperty())
.then((ContextMenu) null)
.otherwise(contextMenu)
);
return row;
});
}
/**
* Resolves table columns based on a ResultSet.
*
* #param resultSet the ResultSet.
* #return
* #throws SQLException
*/
private ObservableList<ObservableList> resolveTableColumns(ResultSet resultSet) throws SQLException {
ObservableList<ObservableList> data = FXCollections.observableArrayList();
for (int i = 0; i < resultSet.getMetaData().getColumnCount(); i++) {
final int j = i;
TableColumn col = new TableColumn(resultSet.getMetaData().getColumnName(i + 1));
col.setCellValueFactory((Callback<TableColumn.CellDataFeatures<ObservableList, String>, ObservableValue<String>>) param -> {
return new SimpleStringProperty(param.getValue().get(j).toString());
});
tableView.getColumns().add(col);
}
return data;
}
/**
* Adds table data from a ResultSet.
*
* #param resultSet the ResultSet.
* #param data the data.
* #throws SQLException
*/
private void addTableRecords(ResultSet resultSet, ObservableList<ObservableList> data) throws SQLException {
while (resultSet.next()) {
ObservableList<String> row = FXCollections.observableArrayList();
for (int i = 1; i <= resultSet.getMetaData().getColumnCount(); i++) {
row.add(resultSet.getString(i));
}
data.add(row);
}
tableView.setItems(data);
}
}
Edit based on #James_D's comment:
package controllers;
import javafx.beans.binding.Bindings;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.value.ObservableValue;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.fxml.FXML;
import javafx.scene.control.*;
import javafx.util.Callback;
import java.sql.ResultSet;
import java.sql.SQLException;
public class TableController {
#FXML
private Label descriptionLabel;
#FXML
private TableView<ObservableList<String>> tableView;
public void setTableResultSet(String label, ResultSet resultSet) throws SQLException {
// Create context menu
createContextMenu();
// Set label text
descriptionLabel.setText(label);
// Resolve columns
ObservableList<ObservableList<String>> data = resolveTableColumns(resultSet);
// Add records
addTableRecords(resultSet, data);
}
/**
* Create a context menu responsible for removing items.
*/
private void createContextMenu() {
tableView.setRowFactory(tableView -> {
final TableRow<ObservableList<String>> row = new TableRow<>();
final ContextMenu contextMenu = new ContextMenu();
final MenuItem removeMenuItem = new MenuItem("Изтрий");
removeMenuItem.setOnAction(event -> {
System.out.println(row.getItem().get(1));
this.tableView.getItems().remove(row.getItem());
});
contextMenu.getItems().add(removeMenuItem);
// Set context menu on row, but use a binding to make it only show for non-empty rows:
row.contextMenuProperty().bind(
Bindings.when(row.emptyProperty())
.then((ContextMenu) null)
.otherwise(contextMenu)
);
return row;
});
}
/**
* Resolves table columns based on a ResultSet.
*
* #param resultSet the ResultSet.
* #return
* #throws SQLException
*/
private ObservableList<ObservableList<String>> resolveTableColumns(ResultSet resultSet) throws SQLException {
ObservableList<ObservableList<String>> data = FXCollections.observableArrayList();
for (int i = 0; i < resultSet.getMetaData().getColumnCount(); i++) {
final int j = i;
TableColumn col = new TableColumn(resultSet.getMetaData().getColumnName(i + 1));
col.setCellValueFactory((Callback<TableColumn.CellDataFeatures<ObservableList, String>, ObservableValue<String>>) param -> {
return new SimpleStringProperty(param.getValue().get(j).toString());
});
tableView.getColumns().add(col);
}
return data;
}
/**
* Adds table data from a ResultSet.
*
* #param resultSet the ResultSet.
* #param data the data.
* #throws SQLException
*/
private void addTableRecords(ResultSet resultSet, ObservableList<ObservableList<String>> data) throws SQLException {
while (resultSet.next()) {
ObservableList<String> row = FXCollections.observableArrayList();
for (int i = 1; i <= resultSet.getMetaData().getColumnCount(); i++) {
row.add(resultSet.getString(i));
}
data.add(row);
}
tableView.setItems(data);
}
}

Answer 1

Don't use raw types: that way you can access the appropriate methods for the data you retrieve from the table (without have to downcast anywhere).
Specifically, you declare you represent your data as an
ObservableList<ObservableList>, which means that each row is represented as a (raw) ObservableList. Since, looking at your addTableRecords method, each element of a row is a String, the rows should be represented as ObservableList<String>, and the overall data as ObservableList<ObservableList<String>>.
The TableView and associated UI elements should also be parameterized: i.e. you should be using
TableView<ObservableList<String>>
TableColumn<ObservableList<String>, String>
TableRow<ObservableList<String>
If you make these changes, then in your createContextMenu() method you will have
TableRow<ObservableList<String>> row = new TableRow<>();
Consequently the return type of row.getItem() will be ObservableList<String> and you can call methods defined in ObservableList (or more generally, List) on the returned value. Specifically, calling get(...) will return the String in a given cell in the row:
String id = row.getItem().get(0);
String name = row.getItem().get(1);
etc.
Put all together, this looks like
package controllers;
import javafx.beans.binding.Bindings;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.value.ObservableValue;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.fxml.FXML;
import javafx.scene.control.*;
import javafx.util.Callback;
import java.sql.ResultSet;
import java.sql.SQLException;
public class TableController {
#FXML
private Label descriptionLabel;
#FXML
private TableView<ObservableList<String>> tableView;
public void setTableResultSet(String label, ResultSet resultSet) throws SQLException {
// Create context menu
createContextMenu();
// Set label text
descriptionLabel.setText(label);
// Resolve columns
ObservableList<ObservableList<String>> data = resolveTableColumns(resultSet);
// Add records
addTableRecords(resultSet, data);
}
/**
* Create a context menu responsible for removing items.
*/
private void createContextMenu() {
tableView.setRowFactory(tableView -> {
final TableRow<ObservableList<String>> row = new TableRow<>();
final ContextMenu contextMenu = new ContextMenu();
final MenuItem removeMenuItem = new MenuItem("Изтрий");
removeMenuItem.setOnAction(event -> {
String id = row.getItem().get(0);
String name = row.getItem().get(1);
// do whatever you need with id and name, etc.
this.tableView.getItems().remove(row.getItem());
});
contextMenu.getItems().add(removeMenuItem);
// Set context menu on row, but use a binding to make it only show for non-empty rows:
row.contextMenuProperty().bind(
Bindings.when(row.emptyProperty())
.then((ContextMenu) null)
.otherwise(contextMenu)
);
return row;
});
}
/**
* Resolves table columns based on a ResultSet.
*
* #param resultSet the ResultSet.
* #return
* #throws SQLException
*/
private ObservableList<ObservableList<String>> resolveTableColumns(ResultSet resultSet) throws SQLException {
ObservableList<ObservableList<String>> data = FXCollections.observableArrayList();
for (int i = 0; i < resultSet.getMetaData().getColumnCount(); i++) {
final int j = i;
TableColumn<ObservableList<String>, String> col = new TableColumn<>(resultSet.getMetaData().getColumnName(i + 1));
col.setCellValueFactory(param ->
new SimpleStringProperty(param.getValue().get(j))
);
tableView.getColumns().add(col);
}
return data;
}
/**
* Adds table data from a ResultSet.
*
* #param resultSet the ResultSet.
* #param data the data.
* #throws SQLException
*/
private void addTableRecords(ResultSet resultSet, ObservableList<ObservableList<String>> data) throws SQLException {
while (resultSet.next()) {
ObservableList<String> row = FXCollections.observableArrayList();
for (int i = 1; i <= resultSet.getMetaData().getColumnCount(); i++) {
row.add(resultSet.getString(i));
}
data.add(row);
}
tableView.setItems(data);
}
}