使用jxl(java)写HYPERLINK excel公式失败

我正在尝试在java中使用jxl编写一个HYPERLINK到excel,但写入失败,如下所示。 请build议可以做些什么

String scn = "=HYPERLINK(\"D:\\snaps\\"+step_num+".jpg\",\"Click\")"; Formula link = new Formula(3,0,scn); wws.addCell(link); java.util.EmptyStackException at java.util.Stack.peek(Unknown Source) at java.util.Stack.pop(Unknown Source) at jxl.biff.formula.BinaryOperator.getOperands(BinaryOperator.java:61) at jxl.biff.formula.StringFormulaParser.parseCurrent(StringFormulaParser.java:240) at jxl.biff.formula.StringFormulaParser.parse(StringFormulaParser.java:113) at jxl.biff.formula.FormulaParser.parse(FormulaParser.java:129) at jxl.write.biff.FormulaRecord.initialize(FormulaRecord.java:160) at jxl.write.biff.FormulaRecord.setCellDetails(FormulaRecord.java:243) at jxl.write.biff.WritableSheetImpl.addCell(WritableSheetImpl.java:1155) at framework.WrapperMethods.writeExcel(WrapperMethods.java:174) at framework.WrapperMethods.setValueById(WrapperMethods.java:80) at sample.T24Login.main(T24Login.java:55) 

通过删除=更改

 String scn = "=HYPERLINK(\"D:\\snaps\\"+step_num+".jpg\",\"Click\")"; 

 String scn = "HYPERLINK(\"D:\\snaps\\"+step_num+".jpg\",\"Click\")";