有关EJB的问题，崩溃中……

ThinkCat 2013-04-25 05:46:28

程序是在用友NC里跑的。

之前在一个接口里定义了一个方法，并对其进行实现，然后生成EJB。在其他类中，引用该方法，一切正常。

这个方法有两个参数，一个是VO，另一个是类型是VO的list。

后来，对其中那个VO进行了一点改动，改了其中一个字段名，然后再生成EJB。然后问题就来了。

Exception in thread "AWT-EventQueue-0" java.lang.AbstractMethodError: nc.itf.scm.qc.SCM_QC_QcEJB50_Local.savePrintMode(Lnc/vo/qc/cert/CertificatePrintModeHeadVO;Ljava/util/List;)V
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:585)
at nc.bs.framework.server.AbstractEJBToBServiceHandler.invoke(AbstractEJBToBServiceHandler.java:79)
at nc.bs.framework.server.AbstractEJBToBServiceHandler.invoke(AbstractEJBToBServiceHandler.java:54)
at $Proxy14.savePrintMode(Unknown Source)
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:585)
at nc.bs.framework.comn.serv.ServiceDispatcher.invokeBeanMethod(ServiceDispatcher.java:325)
at nc.bs.framework.comn.serv.ServiceDispatcher.execCall(ServiceDispatcher.java:132)
at nc.bs.framework.comn.serv.CommonServletDispatcher.doGet(CommonServletDispatcher.java:76)
at nc.bs.framework.comn.serv.CommonServletDispatcher.doPost(CommonServletDispatcher.java:95)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:767)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:860)
at sun.reflect.GeneratedMethodAccessor115.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:243)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAsPrivileged(Subject.java:517)
at org.apache.catalina.security.SecurityUtil.execute(SecurityUtil.java:275)
at org.apache.catalina.security.SecurityUtil.doAsPrivilege(SecurityUtil.java:161)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:245)
at org.apache.catalina.core.ApplicationFilterChain.access$000(ApplicationFilterChain.java:50)
at org.apache.catalina.core.ApplicationFilterChain$1.run(ApplicationFilterChain.java:156)
at java.security.AccessController.doPrivileged(Native Method)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:152)
at nc.bs.framework.server.LoggerServletFilter.doFilter(LoggerServletFilter.java:32)
at sun.reflect.GeneratedMethodAccessor113.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:243)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAsPrivileged(Subject.java:517)
at org.apache.catalina.security.SecurityUtil.execute(SecurityUtil.java:275)
at org.apache.catalina.security.SecurityUtil.doAsPrivilege(SecurityUtil.java:217)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:197)
at org.apache.catalina.core.ApplicationFilterChain.access$000(ApplicationFilterChain.java:50)
at org.apache.catalina.core.ApplicationFilterChain$1.run(ApplicationFilterChain.java:156)
at java.security.AccessController.doPrivileged(Native Method)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:152)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:856)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:744)
at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
at java.lang.Thread.run(Thread.java:595)

红色字体的是我的那个方法。

再后来，咨询了同事，试着清空了开发环境中的有关EJB的文件夹，还试着改了一下这个方法的名称。

但是，一直是这个问题，java.lang.AbstractMethodError。

官方对java.lang.AbstractMethodError的解释是：
“Thrown when an application tries to call an abstract method. Normally, this error is caught by the compiler; this error can only occur at run time if the definition of some class has incompatibly changed since the currently executing method was last compiled.”
也就是通常是在编译的时候就会被catch，运行时发生的唯一情况就是某些类incompatibly changed，这个“incompatibly changed”到底怎么理解。

搞了好几天，崩溃了都，希望大家赐教。

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