我遇到了一个问题，tomcat 在不时请求时没有停止，我必须手动终止该进程。我使用的是标准弹簧堆栈（JPA，MVC）。这并不总是发生，只有大约 70% 的时间。我在 Windows、OSX 和 Linux 平台上都看到过这种情况……
任何想法为什么会发生这种情况.. 在下面的日志中，您将看到 2 个 SERVERE 日志条目，但从这个问题：为了防止内存泄漏，JDBC 驱动程序已被强制注销似乎说这不是 Tomcat 的问题所以它留下了软参考..
任何想法为什么这可以阻止tomcat关闭？
编辑：关于进一步的建议和分析 - 看起来 apache HTTP 客户端正在使用 DateUtils 类，该类又创建一个 ThreadLocal 实例。我们的代码使用 HTTP 客户端对外部服务进行分类......当然这应该是一个非常如果它驻留在 Apache HTTP 客户端中的常见问题，因为使用它来调用外部 HTTP 端点并不少见？
日志输出下方的线程转储
谢谢，
伊恩。
-2013-01-04 09:18:33,189 DEBUG [http-bio-9999-exec-8] view.InternalResourceView (InternalResourceView.java:236) - Forwarding to resource [/WEB-INF/views/auth/login.jsp] in InternalResourceView 'auth/login'
2013-01-04 09:18:33,191 DEBUG [http-bio-9999-exec-8] servlet.FrameworkServlet (FrameworkServlet.java:913) - Successfully completed request
Jan 04, 2013 9:18:33 AM org.apache.catalina.core.StandardServer await
INFO: A valid shutdown command was received via the shutdown port. Stopping the Server instance.
Jan 04, 2013 9:18:33 AM org.apache.coyote.AbstractProtocol pause
INFO: Pausing ProtocolHandler ["http-bio-9999"]
Jan 04, 2013 9:18:33 AM org.apache.coyote.AbstractProtocol pause
INFO: Pausing ProtocolHandler ["ajp-bio-8009"]
Jan 04, 2013 9:18:33 AM org.apache.catalina.core.StandardService stopInternal
INFO: Stopping service Catalina
2013-01-04 09:18:33,409 INFO [localhost-startStop-2] support.AbstractApplicationContext (AbstractApplicationContext.java:1025) - Closing WebApplicationContext for namespace 'test-servlet': startup date [Thu Jan 03 17:56:22 GMT 2013]; parent: Root WebApplicationContext
2013-01-04 09:18:33,409 DEBUG [localhost-startStop-2] support.AbstractBeanFactory (AbstractBeanFactory.java:245) - Returning cached instance of singleton bean 'org.springframework.context.annotation.internalScheduledAnnotationProcessor'
2013-01-04 09:18:33,410 DEBUG [localhost-startStop-2] support.AbstractBeanFactory (AbstractBeanFactory.java:245) - Returning cached instance of singleton bean 'lifecycleProcessor'
2013-01-04 09:18:33,410 INFO [localhost-startStop-2] support.DefaultSingletonBeanRegistry (DefaultSingletonBeanRegistry.java:433) - Destroying singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@37f293d3: defining beans []; parent: org.springframework.beans.factory.support.DefaultListableBeanFactory@2f701b4e
log4j:WARN No appenders could be found for logger (org.springframework.web.context.support.AnnotationConfigWebApplicationContext).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
Jan 04, 2013 9:18:33 AM org.apache.catalina.loader.WebappClassLoader clearReferencesJdbc
SEVERE: The web application [] registered the JDBC driver [com.mysql.jdbc.Driver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
Jan 04, 2013 9:18:33 AM org.apache.catalina.loader.WebappClassLoader checkThreadLocalMapForLeaks
SEVERE: The web application [] created a ThreadLocal with key of type [org.apache.http.impl.cookie.DateUtils$DateFormatHolder$1] (value [org.apache.http.impl.cookie.DateUtils$DateFormatHolder$1@3f94bcde]) and a value of type [java.lang.ref.SoftReference] (value [java.lang.ref.SoftReference@3dfbb36e]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.
Jan 04, 2013 9:18:33 AM org.apache.coyote.AbstractProtocol stop
INFO: Stopping ProtocolHandler ["http-bio-9999"]
Jan 04, 2013 9:18:33 AM org.apache.coyote.AbstractProtocol stop
INFO: Stopping ProtocolHandler ["ajp-bio-8009"]
Jan 04, 2013 9:18:33 AM org.apache.coyote.AbstractProtocol destroy
INFO: Destroying ProtocolHandler ["http-bio-9999"]
Jan 04, 2013 9:18:33 AM org.apache.coyote.AbstractProtocol destroy
INFO: Destroying ProtocolHandler ["ajp-bio-8009"]
--线程转储-----
在 org.apache.http.impl.cookie.DateUtils$DateFormatHolder$1.initialValue(DateUtils.java:220) 在 org.apache.http.impl.cookie.DateUtils$DateFormatHolder$1.initialValue(DateUtils.java:219) 在 java .lang.ThreadLocal.setInitialValue(ThreadLocal.java:160)
at java.lang.ThreadLocal.get(ThreadLocal.java:150) at org.apache.http.impl.cookie.DateUtils$DateFormatHolder.formatFor(DateUtils.java:239 ) 在 org.apache.http.impl.cookie.DateUtils.parseDate(DateUtils.java:156)
在 org.apache.http.impl.cookie.DateUtils.parseDate(DateUtils.java:114) 在 org.apache.http.impl.cookie.BasicExpiresHandler.parse(BasicExpiresHandler.java:61) 在 org.apache.http.impl .cookie.CookieSpecBase.parse(CookieSpecBase.java:93) 在 org.apache.http.impl.cookie.BestMatchSpec.parse(BestMatchSpec.java:135) 在 org.apache.http.client.protocol.ResponseProcessCookies.processCookies(ResponseProcessCookies .java:114) 在 org.apache.http.protocol.ImmutableHttpProcessor.process(ImmutableHttpProcessor.java:116) 在 org.apache.http.protocol.ImmutableHttpProcessor.process(ImmutableHttpProcessor.java:116) 在 org.apache.http.client.protocol.ResponseProcessCookies.process(ResponseProcessCookies.java:95)。 http.protocol.HttpRequestExecutor.postProcess(HttpRequestExecutor.java:342) 在 org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:462) 在 org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:754) 在 org.apache.http .impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:732)