用struts和hibernate做登录出错了。

exception javax.servlet.ServletException: Servlet execution threw an exception
root cause java.lang.NoClassDefFoundError: org/hibernate/Query
com.action.User.<init>(User.java:15)
sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
java.lang.reflect.Constructor.newInstance(Constructor.java:513)
java.lang.Class.newInstance0(Class.java:355)
java.lang.Class.newInstance(Class.java:308)
org.apache.struts.util.RequestUtils.applicationInstance(RequestUtils.java:143)
org.apache.struts.action.RequestProcessor.processActionCreate(RequestProcessor.java:292)
org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:230)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)