用POI解析EXCEL文件报错,高人指点.该如何解决

用POI解析EXCEL文件报错,高人指点.
HSSFWorkbook   workbook   =   null;          
try
{
                workbook   =   new   HSSFWorkbook(new   FileInputStream( "c:\\12.xls "));
}
catch   (IOException   e)
{
                e.printStackTrace();
}
.....
执行下面一句时
workbook   =   new   HSSFWorkbook(new   FileInputStream( "c:\\12.xls "));
抛出异常:

java.io.IOException:   Invalid   header   signature;   read   -1964499853149091405,   expected   -2226271756974174256

at   org.apache.poi.poifs.storage.HeaderBlockReader. <init> (HeaderBlockReader.java:100)

at   org.apache.poi.poifs.filesystem.POIFSFileSystem. <init> (POIFSFileSystem.java:84)

at   org.apache.poi.hssf.usermodel.HSSFWorkbook. <init> (HSSFWorkbook.java:257)

at   org.apache.poi.hssf.usermodel.HSSFWorkbook. <init> (HSSFWorkbook.java:238)

at   com.swan.stock.StockService.parseExcelFile(StockService.java:37)

at   com.swan.stock.StockMainFrameActionAdapter.fileSelect_actionPerformed(StockMainFrameActionAdapter.java:52)

at   com.swan.stock.StockMainFrameActionAdapter.actionPerformed(StockMainFrameActionAdapter.java:33)

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)

java.lang.Exception:   传入的文件不对

at   com.swan.stock.StockService.parseExcelFile(StockService.java:43)

at   com.swan.stock.StockMainFrameActionAdapter.fileSelect_actionPerformed(StockMainFrameActionAdapter.java:52)

at   com.swan.stock.StockMainFrameActionAdapter.actionPerformed(StockMainFrameActionAdapter.java:33)