JTable 导致我的应用程序崩溃

Question

我正在为学校项目创建一个相当简单的应用程序。这是一个联系人管理器。我想在 table 中显示所有联系人，我以前从未使用过 JTables，这让我很困惑。我做了很多研究，我只发现一个线程和我有同样的问题，但它没有答案或任何帮助。

JVM crash when using JTable

这是我创建 table 的代码。请注意，我不想创建任何复杂的东西。只是一个 table，我可以在其中插入和删除数据。就这些了。

String[] columnLabels = {"Name", "Number", "Email", "Address"};
Object[][] data = {{"test 1", "test 2"}, {"test 3", "test 4"}};

JTable table = new JTable(data, columnLabels);

如果我直接插入

JTable table = new JTable(10,4);

然后就可以正常工作了。也许有人可以阐明一些问题，因为我不知道出了什么问题。谢谢 <3

这是控制台告诉我的顺便说一句：

Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: 2
at javax.swing.JTable.getValueAt(Unknown Source)
at javax.swing.JTable.getValueAt(Unknown Source)
at javax.swing.JTable.prepareRenderer(Unknown Source)
at javax.swing.plaf.basic.BasicTableUI.paintCell(Unknown Source)
at javax.swing.plaf.basic.BasicTableUI.paintCells(Unknown Source)
at javax.swing.plaf.basic.BasicTableUI.paint(Unknown Source)
at javax.swing.plaf.ComponentUI.update(Unknown Source)
at javax.swing.JComponent.paintComponent(Unknown Source)
at javax.swing.JComponent.paint(Unknown Source)
at javax.swing.JComponent.paintChildren(Unknown Source)
at javax.swing.JComponent.paint(Unknown Source)
at javax.swing.JViewport.paint(Unknown Source)
at javax.swing.JComponent.paintChildren(Unknown Source)
at javax.swing.JComponent.paint(Unknown Source)
at javax.swing.JComponent.paintChildren(Unknown Source)
at javax.swing.JComponent.paint(Unknown Source)
at javax.swing.JComponent.paintChildren(Unknown Source)
at javax.swing.JComponent.paint(Unknown Source)
at javax.swing.JLayeredPane.paint(Unknown Source)
at javax.swing.JComponent.paintChildren(Unknown Source)
at javax.swing.JComponent.paintToOffscreen(Unknown Source)
at javax.swing.RepaintManager$PaintManager.paintDoubleBuffered(Unknown Source)
at javax.swing.RepaintManager$PaintManager.paint(Unknown Source)
at javax.swing.RepaintManager.paint(Unknown Source)
at javax.swing.JComponent.paint(Unknown Source)
at java.awt.GraphicsCallback$PaintCallback.run(Unknown Source)
at sun.awt.SunGraphicsCallback.runOneComponent(Unknown Source)
at sun.awt.SunGraphicsCallback.runComponents(Unknown Source)
at java.awt.Container.paint(Unknown Source)
at java.awt.Window.paint(Unknown Source)
at javax.swing.RepaintManager.run(Unknown Source)
at javax.swing.RepaintManager.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
at javax.swing.RepaintManager.prePaintDirtyRegions(Unknown Source)
at javax.swing.RepaintManager.access00(Unknown Source)
at javax.swing.RepaintManager$ProcessingRunnable.run(Unknown Source)
at java.awt.event.InvocationEvent.dispatch(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access0(Unknown Source)
at java.awt.EventQueue.run(Unknown Source)
at java.awt.EventQueue.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)

Answer 1

您的模型数组包含 2 行和 2 列，而您的列名数组包含 4 个元素，因此有 4 列。那就是问题所在。提供一个每行有 4 个元素的数据数组（可能为空），它应该可以工作。

来自您正在使用的构造函数的来源：

 public int getRowCount() { return rowData.length; }
 public int getColumnCount() { return columnNames.length; }
 public Object getValueAt(int row, int col) { return rowData[row][col]; }

如您所见，渲染器查看 columnNames 的长度以获得列数（此处为 4）并对其进行迭代（因此为 0 - 3）。最终它调用 getValueAt(0, 2) ，这又调用 rowData[0][2] 并且 - 砰 - col索引超出范围。

相比之下，JTable table = new JTable(10,4); 只是创建了一个 table 具有 10 行和 4 列的空模型：

public JTable(int numRows, int numColumns) {
    this(new DefaultTableModel(numRows, numColumns));
}

JTable 导致我的应用程序崩溃

JTable causes my application to crash

java

crash

swing

jtable