【转载】Tomcat 7.0.3x 启动慢并且遇到StackOverflowError的错误的解决方法

之前使用tomcat7时遇到启动报错问题，日志如下：
严重: ContainerBase.addChild: start:?
org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/mypro]]?
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)?
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:901)?
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877)?
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:633)?
at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1114)?
at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1673)?
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)?
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)?
at java.util.concurrent.FutureTask.run(FutureTask.java:138)?
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)?
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)?
at java.lang.Thread.run(Thread.java:619)?
Caused by: java.lang.IllegalStateException: Unable to complete the scan for annotations for web application [/mypro]. Possible root causes include a too low setting for -Xss and illegal cyclic inheritance dependencies?
at org.apache.catalina.startup.ContextConfig.processAnnotationsStream(ContextConfig.java:2109)?
at org.apache.catalina.startup.ContextConfig.processAnnotationsJar(ContextConfig.java:1981)?
at org.apache.catalina.startup.ContextConfig.processAnnotationsUrl(ContextConfig.java:1947)?
at org.apache.catalina.startup.ContextConfig.processAnnotations(ContextConfig.java:1932)?
at org.apache.catalina.startup.ContextConfig.webConfig(ContextConfig.java:1326)?
at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:878)?
at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:369)?
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119)?
at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90)?
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5179)?
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)?
... 11 more?
Caused by: java.lang.StackOverflowError?
at java.util.HashMap.get(HashMap.java:300)?
at org.apache.catalina.startup.ContextConfig.populateSCIsForCacheEntry(ContextConfig.java:2257)?
at org.apache.catalina.startup.ContextConfig.populateSCIsForCacheEntry(ContextConfig.java:2269)?
at org.apache.catalina.startup.ContextConfig.populateSCIsForCacheEntry(ContextConfig.java:2269)?
at org.apache.catalina.startup.ContextConfig.populateSCIsForCacheEntry(ContextConfig.java:2269)?
at org.apache.catalina.startup.ContextConfig.populateSCIsForCacheEntry(ContextConfig.java:2269)?
at org.apache.catalina.startup.ContextConfig.populateSCIsForCacheEntry(ContextConfig.java:2269)?
……?

在网上找了很久，最终解决问题，在这时MARK一下。以下是解决方法：?

--------------------------------------------------以下文章为转载--------------------------------------------------?

使用tomcat 7.0.3x版本的同学可以发现tomcat启动慢了不少，而且还可能遇到如下启动时异常：?

Unable to complete the scan for annotations for web application [] due to a StackOverflowError. Possible root causes include a too low setting for -Xss and illegal cyclic inheritance dependencies.?

tomcat7.0.3X版本支持servlet3.0的特性，[email protected]@WebListener，要支持这些特性，tomcat就得去扫描所有的jar包里面的每个类。这个异常表明在扫描jar包的时候，递归调用太深，导致栈溢出了，tomcat给了一个馊主意，让你增大xss，这个还是不好，xss加大了，可用线程数就少了。?

分析tomcat源代码，发现它扫描的流程如下：?

1.扫描所有jar包?

2.通过查找jar包中META-INF/services/javax.servlet.ServletContainerInitializer文件内的定义，初始化ServletContainerInitializer实现?

3.如果web.xml中配置了metadata-complete="true" 或者没有找到ServletContainerInitializer实现，都不会继续扫描jar包?

网上大多数的答案的都是说在web.xml中加入了metadata-complete="true"就能避免这个异常。确实在很多场景下，这个异常是能够避免。但是使用spring-web-3.1.0.RELEASE的同学就杯具了，这个jar包中定义了一个ServletContainerInitializer，还是导致了扫描jar包。?

我们可以用另外的办法来解决这个问题，我们让tomcat不扫描指定的jar包，tomcat就要轻松得多了，org.apache.tomcat.util.scan.StandardJarScanner中定义了defaultJarsToSkip，有了这个东东，我们就可以跳过某些jar包。?

如果你不想使用servlet3.0 annotation支持，在tomcat的catalina.properties配置文件中tomcat.util.scan.DefaultJarScanner.jarsToSkip的值后面加一个",*"，这样就不会扫描所有的jar包了。启动更快，也不会出异常。?

tomcat在处理扫描是还有个小bug，比如我遇到了?

SEVERE: Unable to process Jar entry [__MACOSX/cn/****/._HandlerFactory.class] from...?

这是tomcat在扫描到以.class为后缀的文件后，就分析类，很明显，此文件都不是java类文件。tomcat不应该只判断后缀为.class就是java类文件。?

原文地址：http://qingyuexiao.iteye.com/blog/1886059