LinkedList NullPointerException occurs after switched from IBM JVM 1.4.0 to 1.4.1

[Tohru Kao]

Hi,

I encounter a NullPointerException after I switched from IBM JVM 1.4.0 to
IBM JVM 1.4.1.

The component I use is:

Linux 7.3
IBM JVM 1.4.1
freemarker 1.5.2
tomcat 4.1.18

Please give any advice about this NullPointerException which I didn't
encounter in IBM JVM 1.4.0.

Here is the stack trace:

java.lang.NullPointerException
at java.util.LinkedList$ListItr.next(LinkedList.java:510)
at freemarker.template.expression.ExpressionBuilder.associateOperators(ExpressionBuilder.java)
at freemarker.template.expression.ExpressionBuilder.buildExpression(ExpressionBuilder.java)
at freemarker.template.expression.ExpressionBuilder.build(ExpressionBuilder.java)
at freemarker.template.compiler.StandardTemplateParser.parseExpression(StandardTemplateParser.java)
at freemarker.template.compiler.StandardTemplateParser.parseVariable(StandardTemplateParser.java)
at freemarker.template.compiler.StandardTemplateParser.parseVariableInstruction(StandardTemplateParser.java)
at freemarker.template.compiler.StandardTemplateParser.getNextInstruction(StandardTemplateParser.java)
at freemarker.template.compiler.LinkedListTemplateBuilder.buildLinks(LinkedListTemplateBuilder.java)
at freemarker.template.compiler.LinkedListTemplateBuilder.buildGenericBody(LinkedListTemplateBuilder.java)
at freemarker.template.compiler.LinkedListTemplateBuilder.buildStatement(LinkedListTemplateBuilder.java)
at freemarker.template.instruction.GenericStartInstruction.callBuilder(GenericStartInstruction.java)
at freemarker.template.compiler.LinkedListTemplateBuilder.buildLinks(LinkedListTemplateBuilder.java)
at freemarker.template.compiler.LinkedListTemplateBuilder.buildStatement(LinkedListTemplateBuilder.java)
at freemarker.template.instruction.IfInstruction.callBuilder(IfInstruction.java)
at freemarker.template.compiler.LinkedListTemplateBuilder.buildLinks(LinkedListTemplateBuilder.java)
at freemarker.template.compiler.LinkedListTemplateBuilder.build(LinkedListTemplateBuilder.java)
at freemarker.template.Template.compileText(Template.java)
at freemarker.template.Template.compileFromStream(Template.java)
at freemarker.template.Template.compileFromStream(Template.java)
at freemarker.template.Template.compileFromFile(Template.java)
at freemarker.template.Template.(Template.java)
at freemarker.template.FileTemplateCache.loadTemplate(FileTemplateCache.java)
at freemarker.template.FileTemplateCache.getLatestTemplate(FileTemplateCache.java)
at freemarker.template.FileTemplateCache.getTemplate(FileTemplateCache.java)
at org.mytest.HtmlTemplateController.getTemplate(HtmlTemplateController.java:73)
at org.mytest.HtmlTemplateController.getTemplate(HtmlTemplateController.java:99)
at org.mytest.MyServlet.doGet(MyServlet.java:101)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:740)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:247)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:260)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at org.apache.catalina.core.StandardContext.invoke(StandardContext.java:2415)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:180)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispatcherValve.java:170)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:172)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:174)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at org.apache.coyote.tomcat4.CoyoteAdapter.service(CoyoteAdapter.java:223)
at org.apache.jk.server.JkCoyoteHandler.invoke(JkCoyoteHandler.java:261)
at org.apache.jk.common.HandlerRequest.invoke(HandlerRequest.java:360)
at org.apache.jk.common.ChannelSocket.invoke(ChannelSocket.java:632)
at org.apache.jk.common.ChannelSocket.processConnection(ChannelSocket.java:590)
at org.apache.jk.common.SocketConnection.runIt(ChannelSocket.java:707)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:530)
at java.lang.Thread.run(Thread.java:568)

TIA,
-Tohru

 

[Chris]

I suspect that there's a bug in your code that was being silently
ignored in the earlier JVM, but is now being trapped, however the
stack trace isn't much help without seeing some of the code.

Post a fragment where the exception is being thrown from (i.e. where
next() is called) and someone might be able to help.

- sarge