java JTable拖放

Question

我正在尝试实现JTable拖放，我已经能够在这个问题（How do I drag and drop a row in a JTable?）和这个问题（Moving rows in JTable）中提供的解决方案的基础上使它在大部分情况下工作，并根据我的需要稍微调整了一下

我遇到的问题也是，它在大多数情况下都工作得很好，尽管使用了这里（Moving rows in JTable）找到的TableModel，例如拖入一个三行JTable，将第一行拖动到第二行效果很好，但将第一行拖动到第三行下方的底部会导致ArrayIndexOutOfBoundsException，该行将消失。错误发生在以下行：getDataVector（）。添加（至，o）

来自Moving rows in JTable的以下代码出现问题：

public class ReorderableTableModel extends DefaultTableModel implements Reorderable {
    public void reorder(int from, int to) {
         Object o = getDataVector().remove(from);
         getDataVector().add(to, o);
         fireTableDataChanged();
    }
}

Aaron似乎也回答了这个问题，为什么它可能不起作用：Moving rows in JTable尽管我不确定如何在我的场景中实现Aaron的答案

Stacktrace是：

java.lang.ArrayIndexOutOfBoundsException: 2 > 1
    at java.util.Vector.insertElementAt(Vector.java:598)
    at java.util.Vector.add(Vector.java:814)
    at com.testproject.test.table.TableModel.reorder(TableModel.java:25)
    at com.testproject.test.table.TableRowTransferHandler.importData(TableRowTransferHandler.java:49)
    at javax.swing.TransferHandler$DropHandler.drop(TransferHandler.java:1544)
    at java.awt.dnd.DropTarget.drop(DropTarget.java:455)
    at javax.swing.TransferHandler$SwingDropTarget.drop(TransferHandler.java:1282)
    at sun.awt.dnd.SunDropTargetContextPeer.processDropMessage(SunDropTargetContextPeer.java:538)
    at sun.lwawt.macosx.CDropTargetContextPeer.processDropMessage(CDropTargetContextPeer.java:143)
    at sun.awt.dnd.SunDropTargetContextPeer$EventDispatcher.dispatchDropEvent(SunDropTargetContextPeer.java:852)
    at sun.awt.dnd.SunDropTargetContextPeer$EventDispatcher.dispatchEvent(SunDropTargetContextPeer.java:776)
    at sun.awt.dnd.SunDropTargetEvent.dispatch(SunDropTargetEvent.java:48)
    at java.awt.Component.dispatchEventImpl(Component.java:4746)
    at java.awt.Container.dispatchEventImpl(Container.java:2294)
    at java.awt.Component.dispatchEvent(Component.java:4713)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4888)
    at java.awt.LightweightDispatcher.processDropTargetEvent(Container.java:4599)
    at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4461)
    at java.awt.Container.dispatchEventImpl(Container.java:2280)
    at java.awt.Window.dispatchEventImpl(Window.java:2750)
    at java.awt.Component.dispatchEvent(Component.java:4713)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
    at java.awt.EventQueue.access$500(EventQueue.java:97)
    at java.awt.EventQueue$3.run(EventQueue.java:709)
    at java.awt.EventQueue$3.run(EventQueue.java:703)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:86)
    at java.awt.EventQueue$4.run(EventQueue.java:731)
    at java.awt.EventQueue$4.run(EventQueue.java:729)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
    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)

我试图解决这个问题，虽然我无法解决，但解决这个问题的最佳方式是什么

Answer 1

因为您已经从^ {< CD1>}中删除了一个元素，所以您应该考虑到一些^ {{CD2>}成为^ {CD3>}；

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解决方案

public void reorder(int from, int to) {
     Object o = getDataVector().remove(from);
     getDataVector().add(from>to?to:to-1, o);
     fireTableDataChanged();
}

检查from的索引是否大于to。如果是这样的话，我们就知道to的索引没有改变，如果没有改变，就通过删除索引中的一个来改变它