我为我的摇摆应用程序创建压力测试。 swing app调用返回实体List的远程EJB方法。我把远程方法调用放在for循环中，并将max iteration设置为5000次调用服务器，之后我运行2个客户端，但经过一些调用后，服务器抛出异常
应用程序服务器GlassFish 3.01 b22
WARNING: "IOP00010202: (UNKNOWN) Unknown user exception thrown by the server - exception: java.util.ConcurrentModificationException; message: null"
org.omg.CORBA.UNKNOWN: vmcid: SUN minor code: 202 completed: Maybe
at com.sun.corba.ee.impl.logging.ORBUtilSystemException.runtimeexception(ORBUtilSystemException.java:11015)
at com.sun.corba.ee.impl.protocol.CorbaMessageMediatorImpl.convertThrowableToSystemException(CorbaMessageMediatorImpl.java:2075)
at com.sun.corba.ee.impl.protocol.CorbaMessageMediatorImpl.handleThrowableDuringServerDispatch(CorbaMessageMediatorImpl.java:2025)
at com.sun.corba.ee.impl.protocol.CorbaMessageMediatorImpl.handleThrowableDuringServerDispatch(CorbaMessageMediatorImpl.java:1978)
at com.sun.corba.ee.impl.protocol.CorbaServerRequestDispatcherImpl.dispatch(CorbaServerRequestDispatcherImpl.java:289)
at com.sun.corba.ee.impl.protocol.CorbaMessageMediatorImpl.handleRequestRequest(CorbaMessageMediatorImpl.java:1841)
at com.sun.corba.ee.impl.protocol.CorbaMessageMediatorImpl.handleRequest(CorbaMessageMediatorImpl.java:1695)
at com.sun.corba.ee.impl.protocol.CorbaMessageMediatorImpl.handleInput(CorbaMessageMediatorImpl.java:1078)
at com.sun.corba.ee.impl.protocol.giopmsgheaders.RequestMessage_1_2.callback(RequestMessage_1_2.java:221)
at com.sun.corba.ee.impl.protocol.CorbaMessageMediatorImpl.handleRequest(CorbaMessageMediatorImpl.java:797)
at com.sun.corba.ee.impl.protocol.CorbaMessageMediatorImpl.dispatch(CorbaMessageMediatorImpl.java:561)
at com.sun.corba.ee.impl.protocol.CorbaMessageMediatorImpl.doWork(CorbaMessageMediatorImpl.java:2558)
at com.sun.corba.ee.impl.orbutil.threadpool.ThreadPoolImpl$WorkerThread.performWork(ThreadPoolImpl.java:492)
at com.sun.corba.ee.impl.orbutil.threadpool.ThreadPoolImpl$WorkerThread.run(ThreadPoolImpl.java:528)
Caused by: java.util.ConcurrentModificationException
at java.util.ArrayList.writeObject(ArrayList.java:573)
at sun.reflect.GeneratedMethodAccessor35.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.sun.corba.ee.impl.io.IIOPOutputStream.invokeObjectWriter(IIOPOutputStream.java:760)
at com.sun.corba.ee.impl.io.IIOPOutputStream.outputObject(IIOPOutputStream.java:716)
at com.sun.corba.ee.impl.io.IIOPOutputStream.simpleWriteObject(IIOPOutputStream.java:227)
at com.sun.corba.ee.impl.io.ValueHandlerImpl.writeValueInternal(ValueHandlerImpl.java:268)
at com.sun.corba.ee.impl.io.ValueHandlerImpl.writeValueWithVersion(ValueHandlerImpl.java:240)
at com.sun.corba.ee.impl.io.ValueHandlerImpl.writeValue(ValueHandlerImpl.java:193)
at com.sun.corba.ee.impl.encoding.CDROutputStream_1_0.callWriteValue(CDROutputStream_1_0.java:932)
at com.sun.corba.ee.impl.encoding.CDROutputStream_1_0.writeRMIIIOPValueType(CDROutputStream_1_0.java:917)
at com.sun.corba.ee.impl.encoding.CDROutputStream_1_0.write_value(CDROutputStream_1_0.java:1044)
at com.sun.corba.ee.impl.encoding.CDROutputStream_1_0.write_value(CDROutputStream_1_0.java:1057)
at com.sun.corba.ee.impl.encoding.CDROutputStream_1_0.write_value(CDROutputStream_1_0.java:774)
at com.sun.corba.ee.impl.encoding.CDROutputObject.write_value(CDROutputObject.java:681)
at com.sun.corba.ee.impl.io.IIOPOutputStream.writeObjectField(IIOPOutputStream.java:887)
at com.sun.corba.ee.impl.io.IIOPOutputStream.outputClassFields(IIOPOutputStream.java:959)
at com.sun.corba.ee.impl.io.IIOPOutputStream.defaultWriteObjectDelegate(IIOPOutputStream.java:281)
at com.sun.corba.ee.impl.io.IIOPOutputStream.outputObject(IIOPOutputStream.java:718)
at com.sun.corba.ee.impl.io.IIOPOutputStream.simpleWriteObject(IIOPOutputStream.java:227)
at com.sun.corba.ee.impl.io.ValueHandlerImpl.writeValueInternal(ValueHandlerImpl.java:268)
at com.sun.corba.ee.impl.io.ValueHandlerImpl.writeValueWithVersion(ValueHandlerImpl.java:240)
at com.sun.corba.ee.impl.io.ValueHandlerImpl.writeValue(ValueHandlerImpl.java:193)
at com.sun.corba.ee.impl.encoding.CDROutputStream_1_0.callWriteValue(CDROutputStream_1_0.java:932)
at com.sun.corba.ee.impl.encoding.CDROutputStream_1_0.writeRMIIIOPValueType(CDROutputStream_1_0.java:917)
at com.sun.corba.ee.impl.encoding.CDROutputStream_1_0.write_value(CDROutputStream_1_0.java:1044)
at com.sun.corba.ee.impl.encoding.CDROutputStream_1_0.write_value(CDROutputStream_1_0.java:1057)
at com.sun.corba.ee.impl.encoding.CDROutputStream_1_0.write_abstract_interface(CDROutputStream_1_0.java:760)
at com.sun.corba.ee.impl.encoding.CDROutputObject.write_abstract_interface(CDROutputObject.java:709)
at com.sun.corba.ee.impl.javax.rmi.CORBA.Util.writeAbstractObject(Util.java:501)
at com.sun.corba.ee.impl.io.IIOPOutputStream.writeObjectOverride(IIOPOutputStream.java:197)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:322)
at java.util.ArrayList.writeObject(ArrayList.java:570)
at sun.reflect.GeneratedMethodAccessor35.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.sun.corba.ee.impl.io.IIOPOutputStream.invokeObjectWriter(IIOPOutputStream.java:760)
at com.sun.corba.ee.impl.io.IIOPOutputStream.outputObject(IIOPOutputStream.java:716)
at com.sun.corba.ee.impl.io.IIOPOutputStream.simpleWriteObject(IIOPOutputStream.java:227)
at com.sun.corba.ee.impl.io.ValueHandlerImpl.writeValueInternal(ValueHandlerImpl.java:268)
at com.sun.corba.ee.impl.io.ValueHandlerImpl.writeValueWithVersion(ValueHandlerImpl.java:240)
at com.sun.corba.ee.impl.io.ValueHandlerImpl.writeValue(ValueHandlerImpl.java:193)
at com.sun.corba.ee.impl.encoding.CDROutputStream_1_0.callWriteValue(CDROutputStream_1_0.java:932)
at com.sun.corba.ee.impl.encoding.CDROutputStream_1_0.writeRMIIIOPValueType(CDROutputStream_1_0.java:917)
at com.sun.corba.ee.impl.encoding.CDROutputStream_1_0.write_value(CDROutputStream_1_0.java:1044)
at com.sun.corba.ee.impl.encoding.CDROutputStream_1_0.write_value(CDROutputStream_1_0.java:1057)
at com.sun.corba.ee.impl.encoding.CDROutputStream_1_0.write_value(CDROutputStream_1_0.java:774)
at com.sun.corba.ee.impl.encoding.CDROutputObject.write_value(CDROutputObject.java:681)
at com.sun.corba.ee.impl.io.IIOPOutputStream.writeObjectField(IIOPOutputStream.java:887)
at com.sun.corba.ee.impl.io.IIOPOutputStream.outputClassFields(IIOPOutputStream.java:959)
at com.sun.corba.ee.impl.io.IIOPOutputStream.defaultWriteObjectDelegate(IIOPOutputStream.java:281)
at com.sun.corba.ee.impl.io.IIOPOutputStream.outputObject(IIOPOutputStream.java:718)
at com.sun.corba.ee.impl.io.IIOPOutputStream.simpleWriteObject(IIOPOutputStream.java:227)
at com.sun.corba.ee.impl.io.ValueHandlerImpl.writeValueInternal(ValueHandlerImpl.java:268)
at com.sun.corba.ee.impl.io.ValueHandlerImpl.writeValueWithVersion(ValueHandlerImpl.java:240)
at com.sun.corba.ee.impl.io.ValueHandlerImpl.writeValue(ValueHandlerImpl.java:193)
at com.sun.corba.ee.impl.encoding.CDROutputStream_1_0.callWriteValue(CDROutputStream_1_0.java:932)
at com.sun.corba.ee.impl.encoding.CDROutputStream_1_0.writeRMIIIOPValueType(CDROutputStream_1_0.java:917)
at com.sun.corba.ee.impl.encoding.CDROutputStream_1_0.write_value(CDROutputStream_1_0.java:1044)
at com.sun.corba.ee.impl.encoding.CDROutputStream_1_0.write_value(CDROutputStream_1_0.java:1057)
at com.sun.corba.ee.impl.encoding.CDROutputStream_1_0.write_value(CDROutputStream_1_0.java:774)
at com.sun.corba.ee.impl.encoding.CDROutputObject.write_value(CDROutputObject.java:681)
at com.sun.corba.ee.impl.presentation.rmi.DynamicMethodMarshallerImpl$14.write(DynamicMethodMarshallerImpl.java:394)
at com.sun.corba.ee.impl.presentation.rmi.DynamicMethodMarshallerImpl.writeResult(DynamicMethodMarshallerImpl.java:490)
at com.sun.corba.ee.impl.presentation.rmi.ReflectiveTie._invoke(ReflectiveTie.java:180)
at com.sun.corba.ee.impl.protocol.CorbaServerRequestDispatcherImpl.dispatchToServant(CorbaServerRequestDispatcherImpl.java:682)
at com.sun.corba.ee.impl.protocol.CorbaServerRequestDispatcherImpl.dispatch(CorbaServerRequestDispatcherImpl.java:216)
... 9 more
EJB方法返回文件夹实体
@Entity
public class Folders implements Serializable {
private static final long serialVersionUID = 1L;
@Transient
private List<Folders> chileFolders = new ArrayList<Folders>();
@Basic(optional = false)
@Column(name = "FOLDER_GROUP_ID", nullable = false, unique = false)
private long parentFolderId;
//other attributes of folder entity
public Folders() {
}
public List<Folders> getChildes() {
return chileFolders;
}
public void setChildes(List<Folders> foldersList) {
this.chileFolders = foldersList;
}
/**
* removes all elements from transiant field {@link #chileFolders}
*/
public void removeAllChildes() {
chileFolders.removeAll(chileFolders);
}
}
在EJB方法中，我创建了递归选择文件夹实体与它的childes。数据库中的文件夹实体 通过parentFolderId对象映射到其父实体。
@Stateless
public class FolderManager implements FolderManagerRemote {
//remote ejb method
@Override
public Folders findRootFolder() throws RecordDoNotExistException {
//root folder
Folders tempRoot = new Folders();
tempRoot.setId((long) 1);
tempRoot.setParentFolderId(0);
recursionSelectFromRootFolder(tempRoot);
return tempRoot;
}
//recursion select
private void recursionSelectFromRootFolder(Folders root) {
List<Folders> folderList = getChildes(root);
//maybe this is cause of exception ????? removeAllChildes()
root.removeAllChildes();
for (Iterator iterator = folderList.iterator(); iterator.hasNext();) {
Folders folders = (Folders) iterator.next();
List<Folders> childesOfRoot = root.getChildes();
childesOfRoot.add(folders);
root.setChildes(childesOfRoot);
if (hasChildes(folders)) {
recursionSelectFromRootFolder(folders);
}
}
}
}
我使用Folders Entity中的removeAllChildes（）方法删除以前为文件夹选择的子项
有人可以帮忙吗？
答案 0 :(得分：0)
问题似乎是列表列表被两个不同的线程同时序列化和修改。序列化是由远程EJB调用引起的，但要说明修改的位置，我们需要查看一些代码
基于您在堆栈跟踪中有两个这样的事实
at java.util.ArrayList.writeObject(ArrayList.java:570)
您是否将列表列表作为EJB类的成员？您是在EJB调用中修改它还是返回它？