从同一列的组件菜单中删除 JTable 列时出错

Question

我有一个 JTable，其中为 table header 设置了组件菜单。它包含用于删除列的条目。我的问题发生在删除触发组件菜单的同一列时，它似乎将此操作视为正在拖动的列，这导致 ArrayIndexOutOfBoundsException 和 -1。

如何安全地从组件菜单中删除当前列而不引发此错误？

以下是如何触发此类行为的最小示例。只需运行它并删除您所在的同一列（请注意，当您删除最后一列时它似乎有效，但这与我几乎无关）：

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.JMenuItem;
import javax.swing.JPopupMenu;
import javax.swing.JTable;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableColumn;

public class BasicExample extends JFrame {

    private JTable t;
    private DefaultTableModel dtm;

    public BasicExample() {
        init();
    }

    private void init() {
        dtm = new DefaultTableModel(new String[][]{{"a", "b"}, {"c", "d"}}, new String[]{"A", "B"});
        t = new JTable(dtm);
        t.getTableHeader().setComponentPopupMenu(new PopupMenu(t));
        this.setLayout(new BorderLayout());
        add(t.getTableHeader(), BorderLayout.NORTH);
        add(t, BorderLayout.CENTER);
        pack();
        setVisible(true);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }

    public class PopupMenu extends JPopupMenu {

        private JTable table;

        public PopupMenu(JTable table) {
            this.table = table;
            init();
        }

        private void init() {
            for (int i = 0; i < table.getModel().getColumnCount(); i++) {
                String columnName = table.getModel().getColumnName(i);

                JMenuItem item = new JMenuItem(columnName);
                item.addActionListener(new ActionListener() {
                    @Override
                    public void actionPerformed(ActionEvent e) {
                        TableColumn tc = table.getColumn(columnName);
                        table.getColumnModel().removeColumn(tc);
                    }
                });
                this.add(item);
            }
        }
    }

    public static void main(String[] args) {
        BasicExample be = new BasicExample();
    }
}

在堆栈跟踪中，我看到它似乎将该列视为已拖动，因为它在 BasicTableHeaderUI.java 中输入了条件 if (draggedColumn != null) {，而我正在执行的操作实际上并不是拖。完整的堆栈跟踪如下：

Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: -1
    at java.util.Vector.elementData(Vector.java:734)
    at java.util.Vector.elementAt(Vector.java:477)
    at javax.swing.table.DefaultTableColumnModel.getColumn(DefaultTableColumnModel.java:294)
    at javax.swing.plaf.basic.BasicTableHeaderUI.getHeaderRenderer(BasicTableHeaderUI.java:693)
    at javax.swing.plaf.basic.BasicTableHeaderUI.paintCell(BasicTableHeaderUI.java:709)
    at javax.swing.plaf.basic.BasicTableHeaderUI.paint(BasicTableHeaderUI.java:685)
    at javax.swing.plaf.ComponentUI.update(ComponentUI.java:161)
    at javax.swing.JComponent.paintComponent(JComponent.java:780)
    at javax.swing.JComponent.paint(JComponent.java:1056)
    at javax.swing.JComponent.paintToOffscreen(JComponent.java:5210)
    at javax.swing.RepaintManager$PaintManager.paintDoubleBuffered(RepaintManager.java:1579)
    at javax.swing.RepaintManager$PaintManager.paint(RepaintManager.java:1502)
    at javax.swing.RepaintManager.paint(RepaintManager.java:1272)
    at javax.swing.JComponent._paintImmediately(JComponent.java:5158)
    at javax.swing.JComponent.paintImmediately(JComponent.java:4969)
    at javax.swing.RepaintManager.run(RepaintManager.java:831)
    at javax.swing.RepaintManager.run(RepaintManager.java:814)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
    at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:814)
    at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:789)
    at javax.swing.RepaintManager.prePaintDirtyRegions(RepaintManager.java:738)
    at javax.swing.RepaintManager.access00(RepaintManager.java:64)
    at javax.swing.RepaintManager$ProcessingRunnable.run(RepaintManager.java:1732)
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:756)
    at java.awt.EventQueue.access0(EventQueue.java:97)
    at java.awt.EventQueue.run(EventQueue.java:709)
    at java.awt.EventQueue.run(EventQueue.java:703)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:726)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)

如果相关，这发生在 Java 8。更改 JRE/JDK 不是一个选项。

Answer 1

不小心我们的环境中出现了同样的错误，但确实偶尔出现，所以我无法重现它。但是您的示例非常完美，我能够重现我的错误。请参阅下面的代码。

我在调查期间修改了我的答案。旧注释不能反映最新代码。

你的是一个已报告的错误： https://bugs.java.com/bugdatabase/view_bug.do?bug_id=8068824

这是一个基于 bug 解决方法的解决方案：

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JFrame;
import javax.swing.JMenuItem;
import javax.swing.JPopupMenu;
import javax.swing.JTable;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableColumn;

public class BasicExample extends JFrame {
  private JTable t;
  private DefaultTableModel dtm;

  public BasicExample() {
    init();
  }

  private void init() {
    dtm = new DefaultTableModel(new String[][] { { "a", "b" }, { "c", "d" } },
        new String[] { "A", "B" });
    t = new JTable(dtm);

    t.getTableHeader().setComponentPopupMenu(new PopupMenu(t));
    this.setLayout(new BorderLayout());
    add(t.getTableHeader(), BorderLayout.NORTH);
    add(t, BorderLayout.CENTER);
    pack();
    setVisible(true);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  }

  public class PopupMenu extends JPopupMenu {

    private JTable table;

    public PopupMenu(JTable table) {
      this.table = table;
      init();
    }

    private void init() {
      for (int i = 0; i < table.getModel().getColumnCount(); i++) {
        String columnName = table.getModel().getColumnName(i);

        JMenuItem item = new JMenuItem(columnName);
        item.addActionListener(new ActionListener() {
          @Override
          public void actionPerformed(ActionEvent e) {
            TableColumn tc = table.getColumn(columnName);

            t.getTableHeader().setDraggedColumn(null);

            table.getColumnModel().removeColumn(tc);
          }
        });
        this.add(item);
      }
    }
  }

  public static void main(String[] args) {
    BasicExample be = new BasicExample();
  }
}

删除前只需将 draggedColumn 设置为 null。

我一直在挖掘 因为它没有解释为什么在我们的环境中这个错误很少发生并且只在 QA 中发生。 :)

这是代码在我们的环境中的样子（再次感谢非常好的小例子）。

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

import javax.swing.JFrame;
import javax.swing.JMenuItem;
import javax.swing.JPopupMenu;
import javax.swing.JTable;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableColumn;

public class BasicExample extends JFrame {
  private JTable t;
  private DefaultTableModel dtm;

  public BasicExample() {
    init();
  }

  private void init() {
    dtm = new DefaultTableModel(new String[][] { { "a", "b" }, { "c", "d" } },
        new String[] { "A", "B" });
    t = new JTable(dtm);

    PopupMenu lPopupMenu = new PopupMenu(t);

    //    t.getTableHeader().setComponentPopupMenu(new PopupMenu(t));
    t.getTableHeader().addMouseListener(new MouseAdapter() {
      @Override
      public void mousePressed(MouseEvent pE) {
        lPopupMenu.show(pE.getComponent(), pE.getX(), pE.getY());
      }
    });

    this.setLayout(new BorderLayout());
    add(t.getTableHeader(), BorderLayout.NORTH);
    add(t, BorderLayout.CENTER);
    pack();
    setVisible(true);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  }

  public class PopupMenu extends JPopupMenu {

    private JTable table;

    public PopupMenu(JTable table) {
      this.table = table;
      init();
    }

    private void init() {
      for (int i = 0; i < table.getModel().getColumnCount(); i++) {
        String columnName = table.getModel().getColumnName(i);

        JMenuItem item = new JMenuItem(columnName);
        item.addActionListener(new ActionListener() {
          @Override
          public void actionPerformed(ActionEvent e) {
            TableColumn tc = table.getColumn(columnName);

            //            t.getTableHeader().setDraggedColumn(null);

            table.getColumnModel().removeColumn(tc);
          }
        });
        this.add(item);
      }
    }
  }

  public static void main(String[] args) {
    BasicExample be = new BasicExample();
  }
}

与您的代码不同的是我们不使用setComponentPopupMenu()，而是手动显示PopupMenu。并且您的用例不会在我们的代码中产生异常。
为什么？
好问题，我没有答案。
您的代码 JPopupMenu 以某种方式消耗鼠标事件。并使用我们的代码 JPopupMenu 将鼠标事件传播到底层组件。用UI代替tableheader.
就可以看到了这就是我用我们的代码重现异常的方式：在 header 上按下鼠标右键，但不要释放它并继续将鼠标移到弹出窗口上，远离 header。当指针离开 header 时松开右键（这样 header 就不会处理 MOUSE_RELEASED 事件）。获取异常。

Answer 2

一种似乎有效的方法是取消设置菜单项操作中的拖动列：

@Override
public void actionPerformed(ActionEvent e) {
    table.getTableHeader().setDraggedColumn(null);
    TableColumn tc = table.getColumn(columnName);
    table.getColumnModel().removeColumn(tc);
}

应该注意的是，如果使用右键单击拖动 table 并且未选择任何操作或该操作不会导致 table 重绘，这可能会阻止重绘 table。

从同一列的组件菜单中删除 JTable 列时出错

Error when removing JTable column from component menu on same column

java

swing

jtable

jpopupmenu

indexoutofboundsexception