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Heng Xin Tian Tai Ltd. of Beijing City (abbr, HXTT)

HXTT DBF
java.lang.NullPointerException
Fernando Hartmann
2007-03-09 11:47:31.0
We have one Web application that access some legacy DBF files, and because this we are using your JDBC driver and its work like a charm, great job.
But in one of our clients we have some spurious errors that happens in differents parts of the application, always when we try to execute a query. The only difference that I can see is the machine, it is a bi processor computer, other point is that the error happens with more frequency in sections of the application that send parallel queries to the DBFs.


We have a self made pool of connection routine, and this pool send only on command (statement) by connect at a time.

The trace is bellow, can you please help me ?

java.sql.SQLException: java.lang.NullPointerException
at com.hxtt.sql.dbf.i.C(Unknown Source)
at com.hxtt.sql.dbf.i.if(Unknown Source)
at com.hxtt.sql.ce.a(Unknown Source)
at com.hxtt.sql.aw.v(Unknown Source)
at com.hxtt.sql.dc.a(Unknown Source)
at com.hxtt.sql.dc.a(Unknown Source)
at com.hxtt.sql.dc.a(Unknown Source)
at com.hxtt.sql.dc.a(Unknown Source)
at com.hxtt.sql.dc.a(Unknown Source)
at com.hxtt.sql.dc.a(Unknown Source)
at com.hxtt.sql.dc.a(Unknown Source)
at com.hxtt.sql.bm.a(Unknown Source)
at com.hxtt.sql.bm.a(Unknown Source)
at com.hxtt.sql.ag.a(Unknown Source)
at com.hxtt.sql.ag.a(Unknown Source)
at com.hxtt.sql.ag.executeQuery(Unknown Source)
at com.sadig.sadigweb.DBConnection.executaQuery(DBConnection.java:166)
at com.sadig.sadigweb.Favorito.seleciona(Favorito.java:75)
at com.sadig.sadigweb.Kernel.service(Kernel.java:660)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
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:869)
at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664)
at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
at java.lang.Thread.run(Unknown Source)

at com.hxtt.global.SQLState.SQLException(Unknown Source)
at com.hxtt.sql.bm.a(Unknown Source)
at com.hxtt.sql.ag.a(Unknown Source)
at com.hxtt.sql.ag.a(Unknown Source)
at com.hxtt.sql.ag.executeQuery(Unknown Source)
at com.sadig.sadigweb.DBConnection.executaQuery(DBConnection.java:166)
at com.sadig.sadigweb.Favorito.seleciona(Favorito.java:75)
at com.sadig.sadigweb.Kernel.service(Kernel.java:660)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
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:869)
at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664)
at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
at java.lang.Thread.run(Unknown Source)
Re:java.lang.NullPointerException
HXTT Support
2007-03-12 00:31:42.0
I guess that should be a Java issue for shared memory multiprocessors. Please download the latesat package, which should work normally. Thanks.
Re:Re:java.lang.NullPointerException
Fernando Hartmann
2007-03-12 07:11:09.0
Following your instructions I downloaded the last driver package (Release date 2007-03-12) and now the error changed, now I get the following error on the client computer:

java.sql.SQLException: Invalid column: webtabs.tipotab
at com.hxtt.global.SQLState.SQLException(Unknown Source)
at com.hxtt.sql.dc.a(Unknown Source)
at com.hxtt.sql.dc.a(Unknown Source)
at com.hxtt.sql.dc.a(Unknown Source)
at com.hxtt.sql.dc.a(Unknown Source)
at com.hxtt.sql.dc.a(Unknown Source)
at com.hxtt.sql.dc.a(Unknown Source)
at com.hxtt.sql.bm.a(Unknown Source)
at com.hxtt.sql.bm.a(Unknown Source)
at com.hxtt.sql.ag.a(Unknown Source)
at com.hxtt.sql.ag.a(Unknown Source)
at com.hxtt.sql.ag.executeQuery(Unknown Source)
at com.sadig.sadigweb.DBConnection.executaQuery(DBConnection.java:166)
at com.sadig.sadigweb.Favorito.envia(Favorito.java:185)
at com.sadig.sadigweb.Kernel.service(Kernel.java:666)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
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:869)
at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664)
at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
at java.lang.Thread.run(Unknown Source)


The same code (command) runs in other servers (with Windows and Linux too), and is the same that with the old version of driver sometimes work (random).
I restored the anterior version of the driver and the previous behavior is happened again (random errors) but this specific command runs ok.
The command is the following :
SELECT top 1 MODULO.MODCOD FROM modulo,usumod,estnomes,webtabs where MODCSERVER > 1 and usumod.usucod = 'GERENCIAL' and usumod.modcod = modulo.modcod and modulo.modcod = estnomes.modcod and estnomes.codlingua = 'BR' and webtabs.tipotab = 1 and webtabs.modcod = modulo.modcod and estnomes.tipo = 'MN' order by modseq
The Java version is 1.5.0_11

And off course the field exist. :-)
Re:Re:Re:java.lang.NullPointerException
HXTT Support
2007-03-12 18:45:36.0
Please download again.
Re:Re:Re:Re:java.lang.NullPointerException
Fernando Hartmann
2007-03-13 04:10:41.0
Now its ok, thanks for you quick response, thanks a lot.
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