我的错是我不知道我在其中一个在AWS中运行18.04.2的生产Ubuntu服务器中是否打开了自动更新。 Tomcat最近（自动）更新到8.5.39，并且当我们重新启动tomcat8时，我们的代码无法部署，但有以下异常：
Caused by: java.lang.IllegalStateException: Attribute 'javax.websocket.server.ServerContainer' not found in ServletContext at org.springframework.util.Assert.state(Assert.java:73)
当我在tomcat中启用与安全相关的调试消息时，可以看到以下内容：
policy: evaluate codesources:
Policy CodeSource: (file:/usr/lib/jvm/java-8-oracle/jre/lib/ext/* <no signer certificates>)
Active CodeSource: (file:/var/lib/tomcat8/webapps/api/WEB-INF/lib/spring-retry-1.2.2.RELEASE.jar <no signer certificates>)
policy: evaluation (codesource) failed
policy: evaluate codesources:
Policy CodeSource: (file:/usr/java/packages/lib/ext/* <no signer certificates>)
Active CodeSource: (file:/var/lib/tomcat8/webapps/api/WEB-INF/lib/spring-retry-1.2.2.RELEASE.jar <no signer certificates>)
policy: evaluation (codesource) failed
policy: evaluate codesources:
Policy CodeSource: (null <no signer certificates>)
Active CodeSource: (file:/var/lib/tomcat8/webapps/api/WEB-INF/lib/spring-retry-1.2.2.RELEASE.jar <no signer certificates>)
policy: evaluate principals:
Policy Principals: []
Active Principals: []
我真的不知道这些是否相关……我们需要做什么才能使websocket对Spring可见？我不知道此更新之前在此服务器上运行的tomcat的版本，但是我们从未在javax.websocket.server.ServerContainer上找到与该tomcat版本一起运行的异常。是否可以关闭任何tomcat安全检查？