为什么单击 JTable 单元后没有响应？

Question

I have the following sample Java Swing JTable app:

import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.ListSelectionModel;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;

public class JTableListSelectionListener
{
  public static void main(String[] a)
  {
    JFrame frame=new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    final JTable table;

    String[] columnTitles={"A","B","C","D"};
    Object[][] rowData={{"11","12","13","14"},{"21","22","23","24"},{"31","32","33","34"},{"41","42","43","44"}};

    table=new JTable(rowData,columnTitles);

    table.setCellSelectionEnabled(true);
    ListSelectionModel cellSelectionModel=table.getSelectionModel();
    cellSelectionModel.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);

    cellSelectionModel.addListSelectionListener(new ListSelectionListener()
    {
      public void valueChanged(ListSelectionEvent e)
      {
        String selectedData=null;

        int[] selectedRow=table.getSelectedRows();
        int[] selectedColumns=table.getSelectedColumns();

        for (int i=0;i<selectedRow.length;i++)
          for (int j=0;j<selectedColumns.length;j++)
            selectedData=(String)table.getValueAt(selectedRow[i],selectedColumns[j]);
        System.out.println("Selected: "+selectedData);
      }

    });

    frame.add(new JScrollPane(table));
    frame.setLocationRelativeTo(null);
    frame.setSize(300,200);
    frame.setVisible(true);
  }
}

It won't respond if I click on the same row: If I click on "12" then on "13" or first click on "21" then click on "23", why?

[1] How to fix it so no matter where I click in which ever order, it will always output the value in that cell?

[2] How to be able to tell if I have clicked with left mouse button or the right mouse button?

Answer 1

The problem is, the ListSelectionModel for the JTable managers the row selection only, from the JavaDocs

Returns the ListSelectionModel that is used to maintain row selection state.

This means that of the row selection doesn't change, you won't get a notification.

Instead, you probably want to use the ListSelectionModel used by the TableColumnModel , for example...

table.getColumnModel().getSelectionModel().addListSelectionListener(new ListSelectionListener() {
    @Override
    public void valueChanged(ListSelectionEvent e) {
        System.out.println("Selected column");
    }
});