从DefaultTableModel到MVC架构中的JTable获取数据

Question

I'm having a problem with separating The Table Model(in the Model) from my JTable (in the view), My model contains the query needed to get the data from the database with a buildTableModel() method:

Model.java

public static DefaultTableModel buildTableModel(ResultSet rs)
            throws SQLException {

        ResultSetMetaData metaData = rs.getMetaData();

        // names of columns
        Vector<String> columnNames = new Vector<String>();
        int columnCount = metaData.getColumnCount();
        for (int column = 1; column <= columnCount; column++) {
            columnNames.add(metaData.getColumnName(column));
        }

        // data of the table
        Vector<Vector<Object>> data = new Vector<Vector<Object>>();
        while (rs.next()) {
            Vector<Object> vector = new Vector<Object>();
            for (int columnIndex = 1; columnIndex <= columnCount; columnIndex++) {
                vector.add(rs.getObject(columnIndex));
            }
            data.add(vector);
        }

        return new DefaultTableModel(data, columnNames);

    }

    //queries to execute for Jtable model listProduit
    public ResultSet productList()throws SQLException{
        ResultSet rs = stmt.executeQuery("SELECT * from Lot");

        return rs;
    }

View.java

public class View extends JPanel{


    public  DefaultTableModel dt;

    public  JTable productTable;

    private JScrollPane scrolPane;

    public ListProduit(){


        productTable=new JTable(dt);

        this.setLayout(new GroupLayout(this));
        this.setBackground(Color.decode("#CFDBC5"));

        productTable.setPreferredScrollableViewportSize(new Dimension(500,50));
        productTable.setFillsViewportHeight(true);

        scrolPane= new JScrollPane(productTable);
        this.add(scrolPane);

        this.setVisible(true);


    } 

//setter for the table model
public void setDt(DefaultTableModel dt) {
        this.dt = dt;
        this.dt.fireTableDataChanged();
    }

And this is the part where I'm getting the problem:

Controller.java

            try{   //lines of the problem:
                    ResultSet rs= model.productList();
                    DefaultTableModel dtm = Model.buildTableModel(rs);
                    View.setDt(dtm);
                    // Stuff to handle showing the view
                    showFourthCard();
                    panelList.add(4);
                }catch(SQLException ex){
                    ex.printStackTrace();
                }

Apparentlly the JTable can not change the DefaultTbaleModel object that it gets in the first time so when I'm executing I always get a blank JTable, so in short I cannot set a new DefaultTableModel object in my Controller.java .

Note: This works just fine when I'm not using MVC (because I don't have to set the Table Model), so my problem here is mainly with the separation of the JTable from the Table Model.

Answer 1

Apparentlly the JTable can not change the DefaultTbaleModel object that it gets in the first time so when I'm executing I always get a blank JTable, so in short I cannot set a new DefaultTableModel object in my Controller.java.

public void setDt(DefaultTableModel dt) {
    this.dt = dt;
    this.dt.fireTableDataChanged();
} 

The code above only changes the field, it does not change the TableModel of the JTable instance (eg productTable , which is initially set in the constructor). Make a call to the JTable instance itself to actually change the model backing the JTable eg productTable.setModel(dt);