JSTL problems on Tomcat 4.1.x

["Schnitzer, Jeff" <JS...@maxis.com>]

I get an occasional NullPointerException deep in JSTL when running under
load on Tomcat 4.1.x.  This doesn't occur under 4.0.x.  Are the JSTL
tags tested on Tomcat 4.1.x?

When this problem happens, the page half-loads (up to the tag that
fails).  Refreshing the page almost always works fine.  Under heavy
load, maybe 1 in 100 page executions cause this problem.

Here is the deepest stack trace I have managed to obtain (by modifying
the Jakarta taglibs slightly to print a little extra debugging):

2003-02-12 23:11:48,190 ERROR [STDERR] An error occurred while getting
property "player" from an instance of class
com.maxis.tso.community.tool.ThreadTool: java.lang.NullPointerException
2003-02-12 23:11:48,192 ERROR [STDERR]  at
org.apache.taglibs.standard.lang.jstl.Logger.logError(Logger.java:965)
2003-02-12 23:11:48,192 ERROR [STDERR]  at
org.apache.taglibs.standard.lang.jstl.Logger.logError(Logger.java:1173)
2003-02-12 23:11:48,192 ERROR [STDERR]  at
org.apache.taglibs.standard.lang.jstl.ArraySuffix.evaluate(ArraySuffix.j
ava:321)
2003-02-12 23:11:48,192 ERROR [STDERR]  at
org.apache.taglibs.standard.lang.jstl.ComplexValue.evaluate(ComplexValue
.java:146)
2003-02-12 23:11:48,192 ERROR [STDERR]  at
org.apache.taglibs.standard.lang.jstl.ELEvaluator.evaluate(ELEvaluator.j
ava:242)
2003-02-12 23:11:48,193 ERROR [STDERR]  at
org.apache.taglibs.standard.lang.jstl.ELEvaluator.evaluate(ELEvaluator.j
ava:201)
2003-02-12 23:11:48,193 ERROR [STDERR]  at
org.apache.taglibs.standard.lang.jstl.Evaluator.evaluate(Evaluator.java:
138)
2003-02-12 23:11:48,193 ERROR [STDERR]  at
org.apache.taglibs.standard.lang.jstl.Evaluator.evaluate(Evaluator.java:
167)
2003-02-12 23:11:48,193 ERROR [STDERR]  at
org.apache.taglibs.standard.lang.support.ExpressionEvaluatorManager.eval
uate(ExpressionEvaluatorManager.java:112)
2003-02-12 23:11:48,193 ERROR [STDERR]  at
org.apache.taglibs.standard.tag.el.core.IfTag.condition(IfTag.java:95)
2003-02-12 23:11:48,193 ERROR [STDERR]  at
javax.servlet.jsp.jstl.core.ConditionalTagSupport.doStartTag(Conditional
TagSupport.java:122)
2003-02-12 23:11:48,193 ERROR [STDERR]  at
org.apache.jsp.mb_posts_jsp._jspx_meth_c_if_4(mb_posts_jsp.java:3923)
2003-02-12 23:11:48,194 ERROR [STDERR]  at
org.apache.jsp.mb_posts_jsp._jspx_meth_c_if_3(mb_posts_jsp.java:3535)
2003-02-12 23:11:48,194 ERROR [STDERR]  at
org.apache.jsp.mb_posts_jsp._jspService(mb_posts_jsp.java:615)
2003-02-12 23:11:48,194 ERROR [STDERR]  at
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:136)
2003-02-12 23:11:48,194 ERROR [STDERR]  at
javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
2003-02-12 23:11:48,194 ERROR [STDERR]  at
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.ja
va:204)
2003-02-12 23:11:48,194 ERROR [STDERR]  at
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:289)
2003-02-12 23:11:48,194 ERROR [STDERR]  at
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:240)
2003-02-12 23:11:48,194 ERROR [STDERR]  at
javax.servlet.http.HttpServlet.service(HttpServlet.java:853)


Does anyone have any idea what is happening?

Thanks in advance,
Jeff Schnitzer
jschnitzer@maxis.com
The Sims Online

---------------------------------------------------------------------
To unsubscribe, e-mail: taglibs-user-unsubscribe@jakarta.apache.org
For additional commands, e-mail: taglibs-user-help@jakarta.apache.org