                        课程
                    
                        /后端开发
                        
                            /Java
                        
                        /使用Struts2+Hibernate开发学生信息管理功能

在页面修改学生信息时报错

如题，错误如下：

ERROR org.apache.struts2.dispatcher.DefaultDispatcherErrorHandler - Exception occurred during processing request: Unparseable date: ""
java.text.ParseException: Unparseable date: ""
at java.text.DateFormat.parse(Unknown Source) ~[?:1.8.0_51]
at action.StudentsAction.save(StudentsAction.java:67) ~[StudentsAction.class:?]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_51]
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_51]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_51]
at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_51]
at ognl.OgnlRuntime.invokeMethod(OgnlRuntime.java:870) ~[ognl-3.0.6.jar:?]
at ognl.OgnlRuntime.callAppropriateMethod(OgnlRuntime.java:1293) ~[ognl-3.0.6.jar:?]

...

而且点出某一个学生信息的时候没有生日，点击也不会出现小日历可以选择，有哪位高手帮忙看看，谢谢。