Flex 求救！！

java.lang.ClassCastException: flex.messaging.io.amf.ASObject cannot be cast to java.lang.Integer
at com.ebook.actions.SourceManagerAction.execute(SourceManagerAction.java:178)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at flex.messaging.services.remoting.adapters.JavaAdapter.invoke(JavaAdapter.java:421)
at flex.messaging.services.RemotingService.serviceMessage(RemotingService.java:183)
这是从前台往后台传数据时出的错前台是
<mx:DataGrid x="192" y="55" width="100%" height="100%" horizontalScrollPolicy="auto" verticalScrollPolicy="auto" id="tg" styleName="myDataGrid">
<mx:columns>
<mx:DataGridColumn id="res_id" headerText="元素名称" dataField="res_id" visible="false" width="200"/>
<mx:DataGridColumn id="file_name" headerText="元素名称" dataField="file_name" visible="true" width="200"/>
</mx:DataGrid>
req.form.id = this.bookId;

req.form.resId = this.res_id;

req.form.fileName = this.file_name;
后台是：
Integer bid = (Integer)req.getBean("id");

Integer resId = (Integer)req.getBean("resId");

String fileName = (String)req.getBean("fileName");
哪位大侠帮忙解决下。。谢谢。。急！！！！！