Apache Tomcat/9.0.58 reports an error on shutdown: "Failed to clear soft references from ObjectStreamClass$Caches for web application [ROOT]"
The error is reported for web applications: [ROOT], [host-manager], and [manager] -- the only applications deployed in Tomcat. The traceback shows a ClassCastException in org.apache.catalina.loader.WebappClassLoaderBase.clearCache I have searched the FAQ, configuration documentation, and web (google search), but found only framework-specific solutions like "delete the directory, CATALINA_BASE/conf/Catalina/localhost/awi", which doesn't exist in my configuration. There is a reference to ClassCastExceptions in the release notes for Tomcat 9.0.70, but it suggests moving app-specific .jar files to the shared loader. I have loaded none of my own apps -- only the ones that come with tomcat and tomcat-admin. I cannot find any app-specific .jar files in Catalina.properties or anywhere in CATALINA_BASE or its subdirectories. I have updated all software on my Ubuntu machine as of today (4-jan-2022) using "sudo apt-get update; sudo apt-get upgrade". I have rebooted the machine and ensured that no files existed in CATALINA_BASE/lib, but the problem persists. How can I find my configuration error or stale cache data or somehow clean up the shutdown process? I'm running Apache Tomcat 9.0.58 on Ubuntu 22 LTS with openjdk-11 on an AMD 64-bit processor. Both the tomcat package and the openjdk package were loaded using apt-get from the standard Ubuntu repository for Ubuntu 22. Apache Tomcat server startup is normal (no errors reported), but every time it shuts down, errors are reported in catalina.out. See the configuration and error traceback below. ---------------------------------------------- The configuration as reported in catalina.out: [info] Server version name: Apache Tomcat/9.0.58 (Ubuntu) [info] Server built: Jan 6 1970 15:09:28 UTC [info] Server version number: 9.0.58.0 [info] OS Name: Linux [info] OS Version: 5.15.0-56-generic [info] Architecture: amd64 [info] Java Home: /usr/lib/jvm/java-11-openjdk-amd64 [info] JVM Version: 11.0.17+8-post-Ubuntu-1ubuntu222.04 [info] JVM Vendor: Ubuntu [info] CATALINA_BASE: /var/lib/tomcat9 [info] CATALINA_HOME: /usr/share/tomcat9 [info] Command line argument: --add-opens=java.base/java.lang=ALL-UNNAMED [info] Command line argument: --add-opens=java.base/java.io=ALL-UNNAMED [info] Command line argument: --add-opens=java.base/java.util=ALL-UNNAMED [info] Command line argument: --add-opens=java.base/java.util.concurrent=ALL-UNNAMED [info] Command line argument: --add-opens=java.rmi/sun.rmi.transport=ALL-UNNAMED [info] Command line argument: -Djava.util.logging.config.file=/var/lib/tomcat9/conf/logging.properties [info] Command line argument: -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager [info] Command line argument: -Djava.awt.headless=true [info] Command line argument: -Djdk.tls.ephemeralDHKeySize=2048 [info] Command line argument: -Djava.protocol.handler.pkgs=org.apache.catalina.webresources [info] Command line argument: -Dorg.apache.catalina.security.SecurityListener.UMASK=0027 [info] Command line argument: -Dignore.endorsed.dirs= [info] Command line argument: -Dcatalina.base=/var/lib/tomcat9 [info] Command line argument: -Dcatalina.home=/usr/share/tomcat9 [info] Command line argument: -Djava.io.tmpdir=/tmp [info] Loaded Apache Tomcat Native library [1.2.31] using APR version [1.7.0]. [info] APR capabilities: IPv6 [true], sendfile [true], accept filters [false], random [true], UDS [true]. [info] APR/OpenSSL configuration: useAprConnector [false], useOpenSSL [true] [info] OpenSSL successfully initialized [OpenSSL 3.0.2 15 Mar 2022] ----------------------------------------- When the service is shut down using '$ sudo service tomcat9 stop', errors are reported in catalina.out as: [info] Pausing ProtocolHandler ["http-nio-8080"] [info] Stopping service [Catalina] [warning] Failed to clear soft references from ObjectStreamClass$Caches for web application [ROOT] [warning] java.lang.ClassCastException: class java.io.ObjectStreamClass$Caches$1 cannot be cast to class java.util.Map (java.io.ObjectStreamClass$Caches$1 and java.util.Map are in module java.base of loader 'bootstrap') [warning] at org.apache.catalina.loader.WebappClassLoaderBase.clearCache(WebappClassLoaderBase.java:2325) [warning] at org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesObjectStreamClassCaches(WebappClassLoaderBase.java:2300) [warning] at org.apache.catalina.loader.WebappClassLoaderBase.clearReferences(WebappClassLoaderBase.java:1669) [warning] at org.apache.catalina.loader.WebappClassLoaderBase.stop(WebappClassLoaderBase.java:1597) [warning] at org.apache.catalina.loader.WebappLoader.stopInternal(WebappLoader.java:463) [warning] at org.apache.catalina.util.LifecycleBase.stop(LifecycleBase.java:257) [warning] at org.apache.catalina.core.StandardContext.stopInternal(StandardContext.java:5515) [warning] at org.apache.catalina.util.LifecycleBase.stop(LifecycleBase.java:257) [warning] at org.apache.catalina.core.ContainerBase$StopChild.call(ContainerBase.java:1412) [warning] at org.apache.catalina.core.ContainerBase$StopChild.call(ContainerBase.java:1401) [warning] at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) [warning] at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) [warning] at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:140) [warning] at org.apache.catalina.core.ContainerBase.stopInternal(ContainerBase.java:986) [warning] at org.apache.catalina.util.LifecycleBase.stop(LifecycleBase.java:257) [warning] at org.apache.catalina.core.ContainerBase$StopChild.call(ContainerBase.java:1412) [warning] at org.apache.catalina.core.ContainerBase$StopChild.call(ContainerBase.java:1401) [warning] at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) [warning] at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) [warning] at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:140) [warning] at org.apache.catalina.core.ContainerBase.stopInternal(ContainerBase.java:986) [warning] at org.apache.catalina.util.LifecycleBase.stop(LifecycleBase.java:257) [warning] at org.apache.catalina.core.StandardService.stopInternal(StandardService.java:497) [warning] at org.apache.catalina.util.LifecycleBase.stop(LifecycleBase.java:257) [warning] at org.apache.catalina.core.StandardServer.stopInternal(StandardServer.java:979) [warning] at org.apache.catalina.util.LifecycleBase.stop(LifecycleBase.java:257) [warning] at org.apache.catalina.startup.Catalina.stop(Catalina.java:849) [warning] at org.apache.catalina.startup.Catalina$CatalinaShutdownHook.run(Catalina.java:996)
