Guice + Tomcat潜在的内存泄漏
我刚刚开始在我的Tomcat webapp中使用Google Guice，并且每当WAR文件取消部署时，都会在catalina.out文件中注意到以下内容：
May 16, 2011 5:37:24 PM org.apache.catalina.startup.HostConfig checkResources INFO: Undeploying context [/app] May 16, 2011 5:37:24 PM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads SEVERE: A web application appears to have started a thread named [com.google.inject.internal.util.$Finalizer] but has failed to stop it. This is very likely to create a memory leak. May 16, 2011 5:37:24 PM org.apache.catalina.loader.WebappClassLoader clearThreadLocalMap SEVERE: A web application created a ThreadLocal with key of type [null] (value [com.google.inject.internal.InjectorImpl$1@10ace8d]) and a value of type [java.lang.Object[]] (value [[Ljava.lang.Object;@7e9bed]) but failed to remove it when the web application was stopped. To prevent a memory leak, the ThreadLocal has been forcibly removed.
May 16, 2011 5:37:24 PM org.apache.catalina.startup.HostConfig checkResources INFO: Undeploying context [/app] May 16, 2011 5:37:24 PM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads SEVERE: A web application appears to have started a thread named [com.google.inject.internal.util.$Finalizer] but has failed to stop it. This is very likely to create a memory leak. May 16, 2011 5:37:24 PM org.apache.catalina.loader.WebappClassLoader clearThreadLocalMap SEVERE: A web application created a ThreadLocal with key of type [null] (value [com.google.inject.internal.InjectorImpl$1@10ace8d]) and a value of type [java.lang.Object[]] (value [[Ljava.lang.Object;@7e9bed]) but failed to remove it when the web application was stopped. To prevent a memory leak, the ThreadLocal has been forcibly removed.
May 16, 2011 5:37:24 PM org.apache.catalina.startup.HostConfig checkResources INFO: Undeploying context [/app] May 16, 2011 5:37:24 PM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads SEVERE: A web application appears to have started a thread named [com.google.inject.internal.util.$Finalizer] but has failed to stop it. This is very likely to create a memory leak. May 16, 2011 5:37:24 PM org.apache.catalina.loader.WebappClassLoader clearThreadLocalMap SEVERE: A web application created a ThreadLocal with key of type [null] (value [com.google.inject.internal.InjectorImpl$1@10ace8d]) and a value of type [java.lang.Object[]] (value [[Ljava.lang.Object;@7e9bed]) but failed to remove it when the web application was stopped. To prevent a memory leak, the ThreadLocal has been forcibly removed.
有谁知道是什么原因引起的，或者我怎么能阻止它发生？
我只按照此处的说明http://code.google.com/docreader/#p=google-guice&s=google-guice&t=ServletModule
……还没有做过什么花哨的事。 我只有2个servlet和一个filter。
谢谢！
如果你在关闭webapp时得到这个，我不会太担心。 这种类型的资源泄漏应用程序。 关机很常见。 当你经常进行热部署时（即在不杀死JVM的情况下多次部署），它们确实会成为一个问题，但是当冷部署完成时它们不会出现问题（在部署之前完成取消部署/部署重新部署）。
一种常见的策略是您在开发期间进行热部署（因为它们通常比冷部署更快），并且只在资源泄漏开始影响您的性能时才进行冷部署。 然后，在生产中，您将在每次部署时执行冷部署。 鉴于具有此类泄漏的代码/库的数量，尝试消除它们将是很难的IMO。
根据Guice问题630，它应该在下一个Guice版本（截至2011年11月）中修复，即当Guava 依赖关系升级到r10 +时。
根据Guice第288期 ，似乎修复仍未解决。
这有助于我摆脱com.google.inject.internal.InjectorImpl的“SEVERE”日志条目：
injector = null; System.gc();
注入器是Guice.createInjector(...modules...)
我承认，看起来我没有读过关于调用System.gc（）的坏习惯 ，但它完全有道理，因为Guice在内部使用弱引用。
PS Tomcat 8，Java 8，Guice 3.0