取结果集出现异常Servlet.service() for servlet action threw exception

[lishixnew]

23:56:46,000 WARN [RequestProcessor] Unhandled Exception thrown: class java.lang.reflect.UndeclaredThrowableException
23:56:46,000 ERROR [[action]] Servlet.service() for servlet action threw exception
java.lang.InstantiationException: org.jboss.resource.adapter.jdbc.WrappedResultSet
at java.lang.Class.newInstance0(Class.java:340)
at java.lang.Class.newInstance(Class.java:308)
at org.jboss.serial.classmetamodel.ClassMetaData.newInstance(ClassMetaData.java:334)
at org.jboss.serial.persister.RegularObjectPersister.readData(RegularObjectPersister.java:239)
at org.jboss.serial.objectmetamodel.ObjectDescriptorFactory.readObjectDescriptionFromStreaming(ObjectDescriptorFactory.java:412)
at org.jboss.serial.objectmetamodel.ObjectDescriptorFactory.objectFromDescription(ObjectDescriptorFactory.java:82)
at org.jboss.serial.objectmetamodel.DataContainer$DataContainerInput.readObject(DataContainer.java:845)
at org.jboss.serial.io.MarshalledObjectForLocalCalls.get(MarshalledObjectForLocalCalls.java:60)
at org.jboss.ejb3.remoting.IsLocalInterceptor.invokeLocal(IsLocalInterceptor.java:94)
at org.jboss.ejb3.remoting.IsLocalInterceptor.invoke(IsLocalInterceptor.java:70)
at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
at org.jboss.ejb3.stateless.StatelessRemoteProxy.invoke(StatelessRemoteProxy.java:103)
at $Proxy78.findAll(Unknown Source)
at com.hdty.name.RecordActionImpl.SelectXML(RecordActionImpl.java:80)
at com.hdty.action.RecordAction.SelectXML(RecordAction.java:84)
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:597)
at org.apache.struts.actions.DispatchAction.dispatchMethod(DispatchAction.java:270)
at org.apache.struts.actions.DispatchAction.execute(DispatchAction.java:187)
at org.apache.struts.actions.MappingDispatchAction.execute(MappingDispatchAction.java:169)
at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:431)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
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.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
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.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:179)
at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:84)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
at org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:157)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:241)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:580)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
at java.lang.Thread.run(Thread.java:619)

getStatement();
sta.executeQuery(psql);


public void getStatement(){
try {
if(sta==null||con==null){
con=ds.getConnection();
sta=con.createStatement();
}
} catch (SQLException e) {
System.out.println("取得连接异常");
e.printStackTrace();
}
}

public void close() throws SQLException{
if(set!=null){
// if(!set.isClosed()){set.close();}
set.close();
set=null;
}
if(sta!=null){
// if(!sta.isClosed()){sta.close();}
sta.close();
sta=null;
}
if(con!=null){
// if(!con.isClosed()){con.close();}
con.close();
con=null;
}
}
在线等回答出来马上给分

[interpb]

InstantiationException
是试图创建一个接口或者抽象类的对象时的异常

看看你的代码

[lishixnew]

原因，我使用了resulset这个对象向外传时，以经被关闭了，所以异致这种情况。建议使用这个对象之前不要关闭，就算赋值出去也不行，因为赋出去的都是对象引用，操作些类对象最好都加上final