为什么单击 JTable 单元格后没有响应？

Question

我有以下示例 Java Swing JTable 应用程序：

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);
  }
}

如果我点击同一行，它不会响应：
如果我点击“12”然后点击“13”或者先点击“21”然后点击“23”，为什么？

1. 如何解决这个问题，无论我按什么顺序点击，它总是会输出那个单元格中的值？

2. 如何判断我点击的是鼠标左键还是鼠标右键？

Answer 1

问题是，JTable 的 ListSelectionModel 仅管理行选择，来自 JavaDocs

返回用于维护行选择状态的 ListSelectionModel。

这意味着行选择不会改变，您不会收到通知。

相反，您可能想使用TableColumnModel 使用的ListSelectionModel，例如...

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