异常完整信息
严重: Servlet.service() for servlet RegServlet threw exception
java.lang.NoSuchMethodError:
org.objectweb.asm.ClassVisitor.visit(IILjava/lang/String;Ljava/lang/String;[Ljava/lang/String;Ljava/lang/String;)V
at net.sf.cglib.core.ClassEmitter.begin_class(ClassEmitter.java:77)
at net.sf.cglib.core.KeyFactory$Generator.generateClass(KeyFactory.java:173)
at net.sf.cglib.core.DefaultGeneratorStrategy.generate(DefaultGeneratorStrategy.java:25)
at net.sf.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:216)
at net.sf.cglib.core.KeyFactory$Generator.create(KeyFactory.java:145)
at net.sf.cglib.core.KeyFactory.create(KeyFactory.java:117)
at net.sf.cglib.core.KeyFactory.create(KeyFactory.java:108)
at net.sf.cglib.core.KeyFactory.create(KeyFactory.java:104)
at net.sf.cglib.proxy.Enhancer.<clinit>(Enhancer.java:69)
at org.hibernate.proxy.pojo.cglib.CGLIBLazyInitializer.getProxyFactory(CGLIBLazyInitializer.java:117)
at org.hibernate.proxy.pojo.cglib.CGLIBProxyFactory.postInstantiate(CGLIBProxyFactory.java:43)
at org.hibernate.tuple.entity.PojoEntityTuplizer.buildProxyFactory(PojoEntityTuplizer.java:162)
at org.hibernate.tuple.entity.AbstractEntityTuplizer.<init>(AbstractEntityTuplizer.java:135)
at org.hibernate.tuple.entity.PojoEntityTuplizer.<init>(PojoEntityTuplizer.java:55)
at org.hibernate.tuple.entity.EntityEntityModeToTuplizerMapping.<init>(EntityEntityModeToTuplizerMapping.java:56)
at org.hibernate.tuple.entity.EntityMetamodel.<init>(EntityMetamodel.java:295)
at org.hibernate.persister.entity.AbstractEntityPersister.<init>(AbstractEntityPersister.java:434)
at org.hibernate.persister.entity.SingleTableEntityPersister.<init>(SingleTableEntityPersister.java:109)
at org.hibernate.persister.PersisterFactory.createClassPersister(PersisterFactory.java:55)
at org.hibernate.impl.SessionFactoryImpl.<init>(SessionFactoryImpl.java:226)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1294)
at com.centrain.exam.HibernateUtil.<clinit>(HibernateUtil.java:22)
at com.centrain.control.RegServlet.doGet(RegServlet.java:69)
at com.centrain.control.RegServlet.doPost(RegServlet.java:95)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:710)
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:233)
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:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:263)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:584)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
at java.lang.Thread.run(Thread.java:619)</coolcode>
经过各方资料查找，发现是spring 与hibernate集成的时候，两大框架jar包有冲突！
解决办法：
1.去掉类路径上的关于Hibernate的asm开头的jar包以及cglib-2.1.2.jar(可能版本不一样)
asm.jar
asm-attrs.jar
cglib-2.1.2.jar
2.加入Spring中的以下4个lib
asm-2.2.2.jar
asm-commons-2.2.2.jar
asm-util-2.2.2.jar
cglib-nodep-2.1_3.jar
问题完美解决！