swing表格没有数据怎么显示右键

在Swing中，如果你的JTable没有数据显示，想要添加右键菜单操作，即使表中没有数据，你也可以通过设置DefaultTableCellEditor来创建自定义的行为。首先，你需要创建一个RightClickAction，比如：

import javax.swing.*;
import javax.swing.table.DefaultTableCellEditor;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

class RightClickActionListener implements ActionListener {
    @Override
    public void actionPerformed(ActionEvent e) {
        JPopupMenu popup = new JPopupMenu();
        JMenuItem item = new JMenuItem("右键选项");
        popup.add(item);
        popup.show(JOptionPane.getRootFrame(), e.getX(), e.getY());
    }
}

public void setupEmptyTableContextMenu(JTable table) {
    DefaultTableCellEditor editor = new DefaultTableCellEditor() {
        @Override
        public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {
            return super.getTableCellRendererComponent(table, "", isSelected, hasFocus, row, column); // 使用空字符串代替实际数据
        }

        @Override
        public void editingCanceled() {
            RightClickActionListener listener = new RightClickActionListener();
            ActionContext ac = ActionContext.getContext();
            if (ac != null) {
                ac.getActionMap().put("contextMenu", new AbstractAction() {
                    @Override
                    public void actionPerformed(ActionEvent e) {
                        listener.actionPerformed(e);
                    }
                });
            } else {
                table.addMouseListener(new MouseAdapter() {
                    @Override
                    public void mousePressed(MouseEvent e) {
                        if (e.isPopupTrigger()) {
                            listener.actionPerformed(null);
                        }
                    }
                });
            }
        }
    };
    table.setDefaultEditor(Object.class, editor);
}

然后，在初始化或更新表格时，调用`setupEmptyTableContextMenu(table)`函数。当用户在空单元格区域点击鼠标右键时，就会触发右键菜单。