hibernate中proxool连接池，出现异常

Question

Caused by: java.lang.LinkageError: duplicate class definition: $java/lang/Object$$FastClassByCGLIB$$3f697993
at java.lang.ClassLoader.defineClass0(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:537)
... 67 more
16:29:45,931  WARN PojoTuplizer:156 - could not create proxy factory for:co.Test
org.hibernate.HibernateException: CGLIB Enhancement failed: co.Test
at org.hibernate.proxy.CGLIBLazyInitializer.getProxyFactory(CGLIBLazyInitializer.java:108)
at org.hibernate.proxy.CGLIBProxyFactory.postInstantiate(CGLIBProxyFactory.java:42)
at org.hibernate.tuple.PojoTuplizer.buildProxyFactory(PojoTuplizer.java:144)
at org.hibernate.tuple.AbstractTuplizer.<init>(AbstractTuplizer.java:83)
at org.hibernate.tuple.PojoTuplizer.<init>(PojoTuplizer.java:54)
at org.hibernate.tuple.TuplizerLookup.create(TuplizerLookup.java:47)
at org.hibernate.tuple.EntityMetamodel.<init>(EntityMetamodel.java:218)
at org.hibernate.persister.entity.BasicEntityPersister.<init>(BasicEntityPersister.java:400)
at org.hibernate.persister.entity.SingleTableEntityPersister.<init>(SingleTableEntityPersister.java:104)
at org.hibernate.persister.PersisterFactory.createClassPersister(PersisterFactory.java:55)
at org.hibernate.impl.SessionFactoryImpl.<init>(SessionFactoryImpl.java:211)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1005)
at co.HibernateUtil.currentSession(HibernateUtil.java:48)
at co.TestDb.test(TestDb.java:35)
at org.apache.jsp.MyJsp_jsp._jspService(MyJsp_jsp.java:66)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:94)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:324)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:237)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:214)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:198)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:152)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:137)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:118)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:102)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:929)
at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:160)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:799)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:705)
at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:577)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:683)
at java.lang.Thread.run(Thread.java:534)
Caused by: java.lang.ExceptionInInitializerError
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:324)
at net.sf.cglib.proxy.Enhancer.setCallbacksHelper(Enhancer.java:586)
at net.sf.cglib.proxy.Enhancer.setThreadCallbacks(Enhancer.java:579)
at net.sf.cglib.proxy.Enhancer.createUsingReflection(Enhancer.java:601)
at net.sf.cglib.proxy.Enhancer.firstInstance(Enhancer.java:532)
at net.sf.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:220)
at net.sf.cglib.proxy.Enhancer.createHelper(Enhancer.java:373)
at net.sf.cglib.proxy.Enhancer.create(Enhancer.java:281)
at net.sf.cglib.proxy.Enhancer.create(Enhancer.java:640)
at org.hibernate.proxy.CGLIBLazyInitializer.getProxyFactory(CGLIBLazyInitializer.java:94)
... 44 more
Caused by: net.sf.cglib.core.CodeGenerationException: java.lang.reflect.InvocationTargetException-->null
at net.sf.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:236)
at net.sf.cglib.reflect.FastClass$Generator.create(FastClass.java:67)
at net.sf.cglib.proxy.MethodProxy.helper(MethodProxy.java:81)
at net.sf.cglib.proxy.MethodProxy.create(MethodProxy.java:46)
at co.Test$$EnhancerByCGLIB$$d93f56ad.CGLIB$STATICHOOK1(<generated>)
at co.Test$$EnhancerByCGLIB$$d93f56ad.<clinit>(<generated>)
... 57 more
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.GeneratedMethodAccessor56.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at net.sf.cglib.core.ReflectUtils.defineClass(ReflectUtils.java:373)
at net.sf.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:218)
... 62 more
Caused by: java.lang.LinkageError: duplicate class definition: $java/lang/Object$$FastClassByCGLIB$$3f697993
at java.lang.ClassLoader.defineClass0(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:537)
... 67 more
16:29:46,361  INFO SessionFactoryObjectFactory:82 - Not binding factory to JNDI, no JNDI name configured如果不用proxool连接池，则没有问题。hibernate.cfg.xml部分
<property name="hibernate.connection.provider_class">org.hibernate.connection.ProxoolConnectionProvider</property>
<property name="hibernate.proxool.pool_alias">dress</property>
<property name="hibernate.proxool.xml">proxool.xml</property>
proxool.xml文件：
<?xml version="1.0" encoding="UTF-8"?>
 <something-else-entirely>
  <proxool>
    <alias>dress</alias>
    <driver-url>jdbc:mysql://localhost:3306/dress</driver-url>
    <driver-class>com.mysql.jdbc.Driver</driver-class>
    <driver-properties>
      <property name="user" value="root"/>
      <property name="password" value="admin"/>
    </driver-properties>
 <house-keeping-sleep-time>90000</house-keeping-sleep-time>
        <prototype-count>5</prototype-count>
            <maximum-connection-count>20</maximum-connection-count>
        <minimum-connection-count>10</minimum-connection-count>  </proxool>
</something-else-entirely>哪位高手能够回答我的问题呀？帮帮忙，万分感谢！！！！！！

Answer 1

这不是proxool与hibernate的问题
是proxool 与 cglib 的问题。
我也正在找原因

Answer 2

cglib必须要用2.13以上版本。比如： cglib-nodep-2.1_3.jar

Answer 3

好像是pojo没有默认无参数构造方法。
 get org.hibernate.HibernateException: CGLIB Enhancement failed: <classname>?If you use lazy loading with proxies (default for all classes in Hibernate 3), Hibernate needs to subclass your class at runtime. It can't do this if you have a private no-argument constructor. As per documentation, at least package visibility is required.