Question

做了一个向数据库添加的动作，抛出严重异常，工程中用了Hibernate和ExtJs，异常如下：

严重: Servlet.service() for servlet jsp threw exception
java.lang.NoClassDefFoundError: org/hibernate/Session
at com.family168.student.StudentDao.insert(StudentDao.java:54)
at org.apache.jsp.jsp.save_jsp._jspService(save_jsp.java:77)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:393)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:261)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:581)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
at java.lang.Thread.run(Unknown Source)
==================================================================
save.jsp源码：
<%@ page contentType="application/json;charset=utf-8"
import="com.family168.student.*"%>
<%
request.setCharacterEncoding("utf-8");
response.setCharacterEncoding("utf-8");
String id = request.getParameter("id");
String code = request.getParameter("code");
String name = request.getParameter("name");
String sex = request.getParameter("sex");
String age = request.getParameter("age");
String political = request.getParameter("political");
String origin = request.getParameter("origin");
String professional = request.getParameter("professional");
Student student = new Student();
student.setCode(code);
student.setName(name);
student.setSex(Integer.parseInt(sex));
student.setAge(Integer.parseInt(age));
student.setPolitical(political);
student.setOrigin(origin);
student.setProfessional(professional);
StudentDao dao = StudentDao.getInstance();
if (id == null || id.equals("")) {
dao.insert(student);
} else {
student.setId(Long.parseLong(id));
dao.update(student);
}
out.print("{success:true,msg:'保存成功'}");
%>
============================================================
StudentDao.java中相关的源码：
public void insert(Student student) throws Exception {
Session s = null;
Transaction t = null;

try {
s = DbUtils.getSession();
t = s.beginTransaction();
s.save(student);
t.commit();
} catch (RuntimeException e) {
e.printStackTrace();
t.rollback();
}finally{
try {
s.close();
} catch (RuntimeException e) {
e.printStackTrace();
}
}
}
==================================================================
注意：不要说我没导org.hibernate.Session这个包。我已经到过了。

Answer 1

不要说你没有导入org.hibernate.Session这个包，不是我说的
java.lang.NoClassDefFoundError: org/hibernate/Session
系统这么说，肯定有道理
这句话的意思就是没有找到org/hibernate/Session
你是不是只在java文件中import org.hibernate.Session
而米有在lib文件夹里面导入hibernate3.jar这个包，老兄。。。。

Answer 2

从报错内容看是找不到class，应该是DbUtils这个类找不到，少了dbutil.jar吧

追问

DbUtils这个类是我自己写的，就是用来获得session的，
DAO这块我在后台测试了都没问题，就是一部署到服务器，从界面添加数据时报这个异常。
之前我没用Hibernate之前是好好的，就是将与数据库交互的方式有JDBC改成hibernate之后，出现了这么个异常。

追答

哦，你要用hibernate的session了，还用DbUtils去拿session会报错的，因为你拿的不是hibernate的session

追问

看来我有必要贴出我的DbUtils.java了：
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;

public class DbUtils {
private static SessionFactory sf = new Configuration().configure().buildSessionFactory();
public static Session getSession(){
return sf.openSession();
}
}

追答

哦，那么就用debug模式看看dao中那个class找不到吧，毕竟我没有完整代码，不能调试

Answer 3

StudentDao dao = StudentDao.getInstance();
这个配置了吗？