JAVA SWING: Vector used in Default Table Model fails to addElement() added through a for loop

Question

Two Jtables in this example show a challenge am facing. Simply put,one table is a Master table while the second depends on the Master table data. Master table contains data which on column 3 is Boolean, the purpose of the second table is simply to display all data that on column 3 which is true(Names of all Males). In other words, all data that is false as far as column 3 on Master table is concerned is not to be displayed. The problem is that when I ran the code, only one element is displayed in the second table while other data which is 'Boolean=true' is ignored as shown below.

What might be wrong with my code which fails to display all Boolean true data on the second table.NOTE: I also tried to used the DefaultTableModel addRow() method within the loop but also failed to display all data that is true from MasterTable Column 3.

public class ZoomTable extends JFrame{

    JPanel panel;
    Object [] masterColumns = new Object []{"Name","Age","Male"};
    Object [][] masterData = new Object [][]{
       {"Simon",10,new Boolean(true)},
       {"Jane",10,new Boolean(false)},
       {"Hellen",10,new Boolean(false)},
       {"Amos",10,new Boolean(true)},
       {"Brenda",10,new Boolean(false)},
       {"Dennis",10,new Boolean(true)},
       {"Mary",10,new Boolean(false)},
       };
    MasterTableModel mtm = new MasterTableModel(masterData,masterColumns);
    Vector<Vector> maleListData = new Vector<Vector>();
    Vector maleList = new Vector();
    public static void main(String[] args) {
       ZoomTable zoom = new ZoomTable();
       zoom.init();
       zoom.setVisible(true);
       zoom.setSize(new Dimension(600,800));
       zoom.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    }

    void init(){
        panel = new JPanel();
        panel.setLayout(new BorderLayout());
        JTable masterTable = new JTable(masterData,masterColumns);
        JScrollPane spMaster = new JScrollPane();
        spMaster.setViewportView(masterTable);
        panel.add(spMaster,"North");

        Vector <String> tinyColumns = new Vector <String>();       
        tinyColumns.addElement("NAMES OF MALES");

        DefaultTableModel dtm = new           DefaultTableModel(maleListVector(),tinyColumns);
        JTable tinyTable = new JTable(dtm); 
        JScrollPane spTiny = new JScrollPane();
        spTiny.setViewportView(tinyTable);
        panel.add(spTiny,"Center");
        add(panel);
        pack();
    }

    public Vector maleListVector(){
        for(int k = 0;k < mtm.getRowCount();k++){

            if(mtm.getValueAt(k,2).equals(true)){
                String maleName = mtm.getValueAt(k,0).toString();
                maleList.addElement(maleName);
            System.out.println(maleName+" is Male");
            }
            else if(mtm.getValueAt(k,2).equals(false)){
                String femaleName = mtm.getValueAt(k,0).toString();
              System.out.println(femaleName+" is Female");
            }


         }
        maleListData.add(maleList);
     return maleListData;}
}

class MasterTableModel extends AbstractTableModel{
    Object [][] data;
    Object [] cols;

    MasterTableModel(Object[][] masterData, Object[] masterColumns) {
       data = masterData;
       cols = masterColumns;
    }

    @Override
    public int getRowCount() {
        return data.length;
    }

    @Override
    public int getColumnCount() {
       return cols.length;
    }

    @Override
    public Object getValueAt(int rowIndex, int columnIndex) {
       return data[rowIndex][columnIndex];
    }

 }

Answer 1

The data for the DefaultTableModel is a Vector of Vectors.

You only ever add one Vector to the "maleListData" so this means you have a single row with multiple columns of data.

This is easy to verify. Just change your code to:

tinyColumns.addElement("NAMES OF MALES");
tinyColumns.addElement("2");

and you will see another column of data.

So the solution to your problem is to add a new row of data to the Vector for every male item you find:

//maleList.addElement(maleName);
Vector row = new Vector(1);
row.add(maleName);
maleListData.addElement( row );

...

//maleListData.add(maleList);