Skip to Main Content

JavaFX FXML TableView setCellValueFactory with lambda

AD5XJNov 25 2022

I am having a particular problem with my Maven project and getting values from my SQLite3 DAO into a TableView column. I am a complete JavaFX novice so the references to this type problem do not make a solution obvious to me so far.
Any help would be greatly appreciated. Here is snippets of code from the project.
SQLData.java
[code]
public class MyData {
private final IntegerProperty dataid;
public MyData () {
this.dataid = null;
}
// SETTERS AND GETTERS //
public Integer getID() { return dataid.get(); }
public void setID(int intid) { dataid.set(intid); }
}
[/code]

MyDataDAO.java
[code]
ImplMyDataDAO() {
public ResultSet rs;
private String DML;
public ObservableList<QSO> getList() throws SQLException, ClassNotFoundException
{
//Declare a SELECT statement
DML = "SELECT mydata.id as ID;"
//Execute SELECT statement
try
{
ResultSet rsMyData = DBUtil.execQuery(DML); //Get ResultSet from execQuery method
ObservableList<MyData> dataList = getAll(rsMyData); //Send ResultSet to the getAll method and get list object
//Return employee object
return dataList;
}
catch (SQLException e)
{
System.out.println("ImplMyDataDAO::getList 71: select operation has been failed: " + e.getLocalizedMessage());
//Return exception
throw e;
}
finally
{
try
{
DBUtil.close();
}
catch ( SQLException e )
{
System.out.println("ERROR ImplMyDataDAO::getList 87: Error on close(): " + e.getLocalizedMessage());
}
}
}
[/code]
MainWindowController.java
[code]
@FXML private TableView tblLogView;

//defining columns
@FXML private TableColumn<MyData, Number> idCol;
@Override
public void initialize(URL u, ResourceBundle rb )
lstView = FXCollections.observableArrayList();
qso = null;

qsolog = new ImplQsoDAO();  

loadTable();  
try  
{  
  idCol.setCellValueFactory( cellData -> cellData.getValue().getID() );  

}
}
[/code]

The error says:
incompatible types: bad return type in lambda expression
Integer cannot be converted to ObservableValue<Number>
Which to me does not make sense since the getID method should return an integer and I am putting the return value in a cell of type Number ( which to my understanding is proper). Reviewing all the references to tableview, lambda expressions, and ObservableList/ObservableValue have not helped.
So why the requirement of a ObservableValue type and how do I make that conversion to show in the table column?

Comments
Post Details
Added on Nov 25 2022
0 comments
43 views