请问一个关于二维数组赋值的问题

[Frank1982]

代码如下：
public static String tableContent[][] = null;
tableContent = new String[changShangXinXiTable.getRowCount()][changShangXinXiTable.getColumnCount()];
for (int i = 0; i < changShangXinXiTable.getRowCount(); i ++){
for (int j = 0; j < changShangXinXiTable.getColumnCount(); j ++){
tableContent[i][j] = changShangXinXiTable.getValueAt(i, j).toString();
System.out.print(tableContent[i][j]);
}
}

以上是一个数组赋值的一小段程序，其中的table已经得到值了，而且能够把数组print出来，只是这个循环会抛出异常：
java.lang.NullPointerException
at Autosale.AdvancedQueryFrame.jButton1ActionPerformed(AdvancedQueryFrame.java:1631)
at Autosale.AdvancedQueryFrame.access$300(AdvancedQueryFrame.java:18)
at Autosale.AdvancedQueryFrame$5.actionPerformed(AdvancedQueryFrame.java:350)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1786)
at javax.swing.AbstractButton$ForwardActionEvents.actionPerformed(AbstractButton.java:1839)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:420)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:258)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:245)
at java.awt.Component.processMouseEvent(Component.java:5100)
at java.awt.Component.processEvent(Component.java:4897)
at java.awt.Container.processEvent(Container.java:1569)
at java.awt.Component.dispatchEventImpl(Component.java:3615)
at java.awt.Container.dispatchEventImpl(Container.java:1627)
at java.awt.Component.dispatchEvent(Component.java:3477)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:3483)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3198)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3128)
at java.awt.Container.dispatchEventImpl(Container.java:1613)
at java.awt.Window.dispatchEventImpl(Window.java:1606)
at java.awt.Component.dispatchEvent(Component.java:3477)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:456)
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:145)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:137)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:100)

实在是找不出什么问题，请各位帮忙看看，谢谢了

[iversonxk]

不应该是二维数组赋值的问题，问题应该出在别的地方

[Frank1982]

谢谢，我已经找到问题所在了，是toString（）这里对空字段进行了转换

[blueice2002]

恭喜