org.apache.jasper.JasperException：无法为JSP编译类。

org.apache.jasper.JasperException: Unable to compile class for JSP: 

An error occurred at line: 176 in the jsp file: /encrypted.jsp
gn cannot be resolved

173:     <input type="text" name="itt"  value=""  />
174:         </label><br><br><br><br>
175:            <label><b>Generated Key-</b>
176:             <input type="text" name="Gnkey" value="<%=gn%>"/>
177:         </label>
178:  </td>
org.apache.jasper.JasperException: Unable to co