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

Question

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

Answer 1

User.hbm.xml 和User.java 贴出来看看

Answer 2

User.hbm.xml<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- 
    Mapping file autogenerated by MyEclipse Persistence Tools
-->
<hibernate-mapping>
    <class name="com.benben.hibernate.User" table="user" catalog="home">
        <id name="username" type="java.lang.String">
            <column name="username" length="16" />
            <generator class="assigned" />
        </id>
        <property name="password" type="java.lang.String">
            <column name="password" length="16" not-null="true" />
        </property>
    </class>
</hibernate-mapping>

Answer 3

package com.benben.hibernate;/**
 * User generated by MyEclipse Persistence Tools
 */public class User implements java.io.Serializable { // Fields private String username;
private String password; // Constructors /** default constructor */
public User() {
} /** full constructor */
public User(String username, String password) {
this.username = username;
this.password = password;
} // Property accessors public String getUsername() {
return this.username;
} public void setUsername(String username) {
this.username = username;
} public String getPassword() {
return this.password;
} public void setPassword(String password) {
this.password = password;
}}

Answer 4

package com.benben.hibernate;import java.util.Iterator;
import java.util.List;import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.hibernate.LockMode;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.Transaction;
import org.hibernate.criterion.Example;/**
 * Data access object (DAO) for domain model class User.
 * 
 * @see com.benben.hibernate.User
 * @author MyEclipse Persistence Tools
 */public class UserDAO extends BaseHibernateDAO {
private static final Log log = LogFactory.getLog(UserDAO.class);
// property constants
public static final String PASSWORD = "password"; public void save(User transientInstance) {
log.debug("saving User instance");
try {
Session session=getSession();
Transaction tr=session.beginTransaction();
session.save(transientInstance);
tr.commit();
session.flush();
session.close();
log.debug("save successful");
} catch (RuntimeException re) {
log.error("save failed", re);
throw re;
}
} public void delete(User persistentInstance) {
log.debug("deleting User instance");
try {
Session session=getSession();
Transaction tr=session.beginTransaction();
session.delete(persistentInstance);
tr.commit();
session.flush();
session.close();
log.debug("delete successful");
} catch (RuntimeException re) {
log.error("delete failed", re);
throw re;
}
} public User findById(java.lang.String id) {
log.debug("getting User instance with id: " + id);
try {
User instance = (User) getSession().get(
"com.benben.hibernate.User", id);
return instance;
} catch (RuntimeException re) {
log.error("get failed", re);
throw re;
}
} public List findByExample(User instance) {
log.debug("finding User instance by example");
try {
List results = getSession().createCriteria(
"com.benben.hibernate.User").add(Example.create(instance))
.list();
log.debug("find by example successful, result size: "
+ results.size());
return results;
} catch (RuntimeException re) {
log.error("find by example failed", re);
throw re;
}
} public List findByProperty(String propertyName, Object value) {
log.debug("finding User instance with property: " + propertyName
+ ", value: " + value);
try {
String queryString = "from User as model where model."
+ propertyName + "= ?";
Query queryObject = getSession().createQuery(queryString);
queryObject.setParameter(0, value);
return queryObject.list();
} catch (RuntimeException re) {
log.error("find by property name failed", re);
throw re;
}
} public List findByPassword(Object password) {
return findByProperty(PASSWORD, password);
} public List findAll() {
System.out.print("yes");
log.debug("finding all User instances");
try {
String queryString = "from User";
Session session=getSession();
String str="error";
//if(session==null)
//return str;
//else{
Query queryObject = session.createQuery(queryString);
return queryObject.list();
//System.out.print("ok");
//return null;
//}
} catch (RuntimeException re) {
log.error("find all failed", re);
throw re;
}
} public User merge(User detachedInstance) {
log.debug("merging User instance");
try {
User result = (User) getSession().merge(detachedInstance);
log.debug("merge successful");
return result;
} catch (RuntimeException re) {
log.error("merge failed", re);
throw re;
}
} public void attachDirty(User instance) {
log.debug("attaching dirty User instance");
try {
Session session=getSession();
Transaction tr=session.beginTransaction();
session.saveOrUpdate(instance);
session.flush();
session.close();
log.debug("attach successful");
} catch (RuntimeException re) {
log.error("attach failed", re);
throw re;
}
} public void attachClean(User instance) {
log.debug("attaching clean User instance");
try {
getSession().lock(instance, LockMode.NONE);
log.debug("attach successful");
} catch (RuntimeException re) {
log.error("attach failed", re);
throw re;
}
}
public static void main(String[] args){
UserDAO userd=new UserDAO();
List list=userd.findAll(); Iterator it=list.iterator();
User user=new User();
user=(User)it.next();
System.out.print(user.getUsername());
}
}

Answer 5

Caused   by:   org.hibernate.MappingException:   duplicate   import:   com.benben.hibernate.User 是不是有同名类或配置文件啊？

Answer 6

你好好检查你的数据表的建立与User.hbm.xml和User.java定义的是不是一致？   

Answer 7

<id   name="username"   type="java.lang.String"> 
????????????

Answer 8

关键是我用main方法测试没有问题了，只是在jsp不能用

Answer 9

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！

Answer 10

请问10楼我该检查web.xml还是User.hbm.xml呢？我没有往web.xml写东西呀？

Answer 11

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

Answer 12

查看hibernte.hbm.xml是不是有两个<com/benbean/hibernate/User.hbm.xml>字样

Answer 13

Caused   by:   org.hibernate.MappingException:   duplicate   import:   com.benben.hibernate.User 是不是在JSP页面里引用了2次？com.benben.hibernate.User 
还有就是hibernate.hbm.xml里是不是对user,hbm.xml引用了两次？