最近系统出现些奇怪的问题，抛出信息如下：

ERROR /ServiceAction/com.velcro.workflow.workflow.servlet.WfViewAction(http-0.0.0.0-38080-7) :Servlet execution threw an exception

javax.servlet.ServletException: Servlet execution threw an exception

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:313)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

at org.springframework.orm.hibernate3.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:198)

at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:96)

at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

at org.acegisecurity.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:265)

at org.acegisecurity.ui.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:124)

at org.acegisecurity.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:275)

at org.acegisecurity.ui.basicauth.BasicProcessingFilter.doFilter(BasicProcessingFilter.java:174)

at org.acegisecurity.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:275)

at org.acegisecurity.ui.AbstractProcessingFilter.doFilter(AbstractProcessingFilter.java:271)

at org.acegisecurity.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:275)

at org.acegisecurity.context.HttpSessionContextIntegrationFilter.doFilter(HttpSessionContextIntegrationFilter.java:249)

at org.acegisecurity.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:275)

at org.acegisecurity.util.FilterChainProxy.doFilter(FilterChainProxy.java:149)

at org.acegisecurity.util.FilterToBeanProxy.doFilter(FilterToBeanProxy.java:98)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)

at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)

at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:182)

at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:84)

at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)

at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)

at org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:157)

at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)

at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:262)

at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)

at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)

at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:446)

at java.lang.Thread.run(Thread.java:595)

Caused by: java.lang.StackOverflowError

at java.util.regex.Pattern$BitClass.match(Pattern.java:2869)

at java.util.regex.Pattern$Branch.match(Pattern.java:4530)

at java.util.regex.Pattern$GroupHead.match(Pattern.java:4570)

at java.util.regex.Pattern$Loop.match(Pattern.java:4697)

at java.util.regex.Pattern$GroupTail.match(Pattern.java:4629)

at java.util.regex.Pattern$BitClass.match(Pattern.java:2876)

at java.util.regex.Pattern$Branch.match(Pattern.java:4530)

at java.util.regex.Pattern$GroupHead.match(Pattern.java:4570)

at java.util.regex.Pattern$Loop.match(Pattern.java:4697)

at java.util.regex.Pattern$GroupTail.match(Pattern.java:4629)

at java.util.regex.Pattern$BitClass.match(Pattern.java:2876)

at java.util.regex.Pattern$Branch.match(Pattern.java:4530)

……

很久没攻技术难点了，很是兴奋，就开始对此问题进行了解，观察下发现，有以下规律出现：

1、虽然方法栈溢出，但服务器还可以正常运行，并没有宕机。

2、目前部分时候可以出现此问题。

最后，试探性的考虑了下，是否觉得方法栈空间不够；所以在启动时，加大方法栈空间，参数为-Xss512k，重新启动后，问题得到解决。

不过也很奇怪通常情况下，栈空间的默认值是够用的，以后还需要对代码进行更深入的研究。

这几天，测试下来发现问题没有想象的那么简单，因为通过多次测试后发现，在增加栈空间后，还是会抛出这个错误，暂没查出原因，我将继续关注……

找出问题所在。