线程错误（jdom.jar（太多打开的文件））

Question

我正在做一个线程在DB中创建一些插入，而Ajax方法每隔0.5s向该线程发送请求以检查该过程。 过了一段时间，我得到了卡塔林纳输出中的下一个异常，并且线程死亡。

任何人都可以解释我做错了什么？

我使用tomcat 7和struts 2.0。

java.lang.reflect.InvocationTargetException 
at sun.reflect.GeneratedMethodAccessor69.invoke(Unknown Source) 
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) 
at java.lang.reflect.Method.invoke(Method.java:616) 
at com.googlecode.jsonplugin.JSONWriter.bean(JSONWriter.java:274) 
at com.googlecode.jsonplugin.JSONWriter.process(JSONWriter.java:161) 
at com.googlecode.jsonplugin.JSONWriter.value(JSONWriter.java:115) 
at com.googlecode.jsonplugin.JSONWriter.array(JSONWriter.java:509) 
at com.googlecode.jsonplugin.JSONWriter.process(JSONWriter.java:143) 
at com.googlecode.jsonplugin.JSONWriter.value(JSONWriter.java:115) 
at com.googlecode.jsonplugin.JSONWriter.add(JSONWriter.java:383) 
at com.googlecode.jsonplugin.JSONWriter.bean(JSONWriter.java:275) 
at com.googlecode.jsonplugin.JSONWriter.process(JSONWriter.java:161) 
at com.googlecode.jsonplugin.JSONWriter.value(JSONWriter.java:115) 
at com.googlecode.jsonplugin.JSONWriter.add(JSONWriter.java:383) 
at com.googlecode.jsonplugin.JSONWriter.bean(JSONWriter.java:275) 
at com.googlecode.jsonplugin.JSONWriter.process(JSONWriter.java:161) 
at com.googlecode.jsonplugin.JSONWriter.value(JSONWriter.java:115) 
at com.googlecode.jsonplugin.JSONWriter.map(JSONWriter.java:430) 
at com.googlecode.jsonplugin.JSONWriter.process(JSONWriter.java:140) 
at com.googlecode.jsonplugin.JSONWriter.value(JSONWriter.java:115) 
at com.googlecode.jsonplugin.JSONWriter.add(JSONWriter.java:383) 
at com.googlecode.jsonplugin.JSONWriter.bean(JSONWriter.java:275) 
at com.googlecode.jsonplugin.JSONWriter.process(JSONWriter.java:161) 
at com.googlecode.jsonplugin.JSONWriter.value(JSONWriter.java:115) 
at com.googlecode.jsonplugin.JSONWriter.write(JSONWriter.java:82) 
at com.googlecode.jsonplugin.JSONUtil.serialize(JSONUtil.java:98) 
at com.googlecode.jsonplugin.JSONResult.execute(JSONResult.java:179) 
at com.opensymphony.xwork2.DefaultActionInvocation.executeResult(DefaultActionInvocation.java:362) 
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:266) 
at com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:165) 
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87) 
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237) 
at com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:252) 
at org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68) 
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87) 
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237) 
at com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:122) 
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237) 
at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195) 
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87) 
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237) 
at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195) 
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87) 
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237) 
at com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:179) 
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237) 
at org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:93) 
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237) 
at org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:235) 
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237) 
at com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:89) 
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237) 
at com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:130) 
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237) 
at org.apache.struts2.interceptor.ProfilingActivationInterceptor.intercept(ProfilingActivationInterceptor.java:104) 
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237) 
at org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:267) 
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237) 
at com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:126) 
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237) 
at com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:138) 
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87) 
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237) 
at com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:165) 
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237) 
at org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164) 
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237) 
at com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:179) 
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237) 
at com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:176) 
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237) 
at com.humanlike.web.interceptors.LoginInterceptor.intercept(LoginInterceptor.java:57) 
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237) 
at org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:52) 
at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:468) 
at org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:395) 
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) 
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) 
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:224) 
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169) 
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472) 
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168) 
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100) 
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:929) 
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118) 
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:405) 
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:964) 
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:515) 
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:304) 
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110) 
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603) 
at java.lang.Thread.run(Thread.java:636) 

Caused by: java.io.FileNotFoundException: /usr/local/tomcat_demo/apache-tomcat-7.0.22/webapps/demo2/WEB-INF/lib/jdom.jar (Too many open files) 
at java.io.FileInputStream.open(Native Method) 
at java.io.FileInputStream.<init>(FileInputStream.java:137) 
at java.io.FileInputStream.<init>(FileInputStream.java:96) 
at sun.net.www.protocol.file.FileURLConnection.connect(FileURLConnection.java:87) 
at sun.net.www.protocol.file.FileURLConnection.getInputStream(FileURLConnection.java:178) 
at java.net.URLConnection.getContent(URLConnection.java:705) 
at java.net.URL.getContent(URL.java:1043) 
... 92 more 

Answer 1

在linux中有多少文件可以打开任何进程是有限制的。在Linux中的文件比在Windows中更宽（除了普通文件，还有套接字，管道......）。在你的代码中的某处，你打开了太多的文件，或者可能是套接字。所以试着找出你有资源泄漏的地方。

Answer 2

您正在使用Struts 2并通过Ajax从客户端发送请求。检查是否真的需要为每个请求创建单独的线程。

Struts 2为每个新请求创建一个新的Action对象。所以我认为你不需要创建线程。