strange error

[Rema Remulta]

hi everyone,
Do you have some idea(s) why i'm having this strange error: concurrent modification exception when i connect the java app via jdbc to MySQL server ? Haven't encoutered this when such java app is connecting to MS Access db.

[Jamie Robertson]

Are you sure this is a SQLException? I have only seen these happen while using the Collections classes:
from the docs on Collections
"They have fail-fast iterators, which throw a ConcurrentModificationException in response to concurrent modification of the the backing collection rather than behaving non-deterministically. The Collections class contains static factories called synchronization wrappers that may be used to add synchronization to any unsynchronized collection. All of the new implementations have fail-fast iterators, which detect illegal concurrent modification, and fail quickly and cleanly."
Cut and paste the actual Exception message and the line that is causing the exception, that could help us help you better.
Jamie

[Rema Remulta]

Hi,
Here's the following that displays on tomcat:
2003-07-25 08:36:11 - Ctx( /payroll ): Exception in: R( /payroll + /dbase + null) - java.uti
l.ConcurrentModificationException
at java.util.HashMap$HashIterator.nextEntry(HashMap.java:762)
at java.util.HashMap$KeyIterator.next(HashMap.java:798)
at com.mysql.jdbc.Connection.closeAllOpenStatements(Connection.java:2538)
at com.mysql.jdbc.Connection.close(Connection.java:1067)
at payroll.servlets.PayrollDatabaseServlet.executeQuery(PayrollDatabaseServlet.java:
238)
at payroll.servlets.PayrollDatabaseServlet.executeRequest(PayrollDatabaseServlet.jav
a:176)
at payroll.servlets.PayrollDatabaseServlet.service(PayrollDatabaseServlet.java:81)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.tomcat.core.ServletWrapper.doService(ServletWrapper.java:404)
at org.apache.tomcat.core.Handler.service(Handler.java:286)
at org.apache.tomcat.core.ServletWrapper.service(ServletWrapper.java:372)
at org.apache.tomcat.core.ContextManager.internalService(ContextManager.java:797)
at org.apache.tomcat.core.ContextManager.service(ContextManager.java:743)
at org.apache.tomcat.service.http.HttpConnectionHandler.processConnection(HttpConnec
tionHandler.java:210)
at org.apache.tomcat.service.TcpWorkerThread.runIt(PoolTcpEndpoint.java:416)
at org.apache.tomcat.util.ThreadPool$ControlRunnable.run(ThreadPool.java:498)
at java.lang.Thread.run(Thread.java:536)
Tomcat: Jakarta-Tomcat-3.2.1
JSDK: Version 1.4.0_01

[Dirk Schreckmann]

rema r.,
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