hibernate3.0的一个问题，研究好几天了？？？？？？高手进，技术一般的回答不了
所有的方法在main测试没有问题，可以正常输出数据库的结果，可是在jsp里就报如下错误，困扰我好久了，帮忙看看，谢谢
%%%% Error Creating SessionFactory %%%%
org.hibernate.MappingException: Error reading resource: com/benben/hibernate/User.hbm.xml
at org.hibernate.cfg.Configuration.addResource(Configuration.java:452)
at org.hibernate.cfg.Configuration.parseMappingElement(Configuration.java:1263)
at org.hibernate.cfg.Configuration.parseSessionFactory(Configuration.java:1235)
at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:1217)
at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:1184)
at org.hibernate.cfg.Configuration.configure(Configuration.java:1112)
at com.benben.hibernate.HibernateSessionFactory.<clinit>(HibernateSessionFactory.java:30)
at com.benben.hibernate.BaseHibernateDAO.getSession(BaseHibernateDAO.java:15)
at com.benben.hibernate.UserDAO.save(UserDAO.java:29)
at org.apache.jsp.database_jsp._jspService(database_jsp.java:59)
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)
Caused by: org.hibernate.MappingException: java.lang.SecurityException: class "org.apache.commons.collections.SequencedHashMap"'s signer information does not match signer information of other classes in the same package
at org.hibernate.cfg.Configuration.addInputStream(Configuration.java:408)
at org.hibernate.cfg.Configuration.addResource(Configuration.java:449)
... 27 more
Caused by: java.lang.SecurityException: class "org.apache.commons.collections.SequencedHashMap"'s signer information does not match signer information of other classes in the same package
at java.lang.ClassLoader.checkCerts(Unknown Source)
at java.lang.ClassLoader.preDefineClass(Unknown Source)
at java.lang.ClassLoader.defineClass(Unknown Source)
at java.security.SecureClassLoader.defineClass(Unknown Source)
at org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:1817)
at org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:872)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1325)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1204)
at java.lang.ClassLoader.loadClassInternal(Unknown Source)
at org.hibernate.mapping.Table.<init>(Table.java:32)
at org.hibernate.cfg.Mappings.addTable(Mappings.java:120)
at org.hibernate.cfg.HbmBinder.bindRootPersistentClassCommonValues(HbmBinder.java:251)
at org.hibernate.cfg.HbmBinder.bindRootClass(HbmBinder.java:236)

at org.hibernate.cfg.HbmBinder.bindRoot(HbmBinder.java:152)
at org.hibernate.cfg.Configuration.add(Configuration.java:362)
at org.hibernate.cfg.Configuration.addInputStream(Configuration.java:400)
... 28 more
%%%% Error Creating SessionFactory %%%%
org.hibernate.MappingException: Error reading resource: com/benben/hibernate/User.hbm.xml
at org.hibernate.cfg.Configuration.addResource(Configuration.java:452)
at org.hibernate.cfg.Configuration.parseMappingElement(Configuration.java:1263)
at org.hibernate.cfg.Configuration.parseSessionFactory(Configuration.java:1235)
at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:1217)
at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:1184)
at org.hibernate.cfg.Configuration.configure(Configuration.java:1112)
at com.benben.hibernate.HibernateSessionFactory.rebuildSessionFactory(HibernateSessionFactory.java:69)
at com.benben.hibernate.HibernateSessionFactory.getSession(HibernateSessionFactory.java:53)
at com.benben.hibernate.BaseHibernateDAO.getSession(BaseHibernateDAO.java:15)
at com.benben.hibernate.UserDAO.save(UserDAO.java:29)
at org.apache.jsp.database_jsp._jspService(database_jsp.java:59)
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)
Caused by: org.hibernate.MappingException: duplicate import: com.benben.hibernate.User
at org.hibernate.cfg.Mappings.addImport(Mappings.java:105)
at org.hibernate.cfg.HbmBinder.bindPersistentClassCommonValues(HbmBinder.java:541)
at org.hibernate.cfg.HbmBinder.bindClass(HbmBinder.java:488)
at org.hibernate.cfg.HbmBinder.bindRootClass(HbmBinder.java:234)
at org.hibernate.cfg.HbmBinder.bindRoot(HbmBinder.java:152)
at org.hibernate.cfg.Configuration.add(Configuration.java:362)
at org.hibernate.cfg.Configuration.addInputStream(Configuration.java:400)
at org.hibernate.cfg.Configuration.addResource(Configuration.java:449)
... 28 more
2008-1-2 14:09:51 org.apache.catalina.core.StandardWrapperValve invoke
严重: Servlet.service() for servlet jsp threw exception
java.lang.NullPointerException
at com.benben.hibernate.UserDAO.save(UserDAO.java:30)
at org.apache.jsp.database_jsp._jspService(database_jsp.java:59)
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

[解决办法]
Caused by: org.hibernate.MappingException: duplicate import: com.benben.hibernate.User
重复加载配置文件

web 程序在启动的时候加载一次，在你的程序里肯定又加载一次；
在main里好用是因为，没有web加载，所以只加载一次，所以好用；
你检查一下你的配置文件！
[解决办法]
是配置文件的问题:
在你的MYEECLIPSE里面用搜索功能,搜索关键字"User"
即能找到所有引用此类的JAVA,和XML等等文本文件
你再一个一个对比,就能发现是哪个地方多引用了