部署不同分支Vaadin应用至Tomcat启动失败，需清理哪些序列化数据？

问题 #

将代码另一分支的同名Vaadin应用部署到Linux环境的同一Apache Tomcat服务器上，Tomcat启动时出现序列化不兼容错误，导致应用无法启动，错误日志如下：

SEVERE: Exception loading sessions from persistent storage
java.io.InvalidClassException: com.vaadin.server.AbstractClientConnector; local class incompatible: stream classdesc serialVersionUID = 4820326152100553455, local class serialVersionUID = 2157417212878694211
at java.base/java.io.ObjectStreamClass.initNonProxy(ObjectStreamClass.java:560)
    at java.base/java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:2020)
    at java.base/java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1870)
    at java.base/java.io.ObjectInputStream.readClass(ObjectInputStream.java:1833)
    at java.base/java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1658)
    at java.base/java.io.ObjectInputStream.readObject(ObjectInputStream.java:489)
    at java.base/java.io.ObjectInputStream.readObject(ObjectInputStream.java:447)
    at java.base/java.util.HashMap.readObject(HashMap.java:1464)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    at java.base/java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:1046)
    at java.base/java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:2357)
    at java.base/java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2228)
    at java.base/java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1687)
    at java.base/java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2496)
    at java.base/java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:2390)
    at java.base/java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2228)
    at java.base/java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1687)
    at java.base/java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2496)
    at java.base/java.io.ObjectInputStream.defaultReadObject(ObjectInputStream.java:625)
    at com.vaadin.server.VaadinSession.readObject(VaadinSession.java:1470)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    at java.base/java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:1046)
    at java.base/java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:2357)
    at java.base/java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2228)
    at java.base/java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1687)
    at java.base/java.io.ObjectInputStream.readObject(ObjectInputStream.java:489)
    at java.base/java.io.ObjectInputStream.readObject(ObjectInputStream.java:447)
    at org.apache.catalina.session.StandardSession.doReadObject(StandardSession.java:1533)
    at org.apache.catalina.session.StandardSession.readObjectData(StandardSession.java:1003)
    at org.apache.catalina.session.StandardManager.doLoad(StandardManager.java:210)
    at org.apache.catalina.session.StandardManager.load(StandardManager.java:156)
    at org.apache.catalina.session.StandardManager.startInternal(StandardManager.java:346)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:4963)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:683)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:658)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:662)
    at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:1023)
    at org.apache.catalina.startup.HostConfig$DeployWar.run(HostConfig.java:1910)
    at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
    at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
    at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75)
    at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:118)
    at org.apache.catalina.startup.HostConfig.deployWARs(HostConfig.java:824)
    at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:474)
    at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1617)
    at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:318)
    at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:123)
    at org.apache.catalina.util.LifecycleBase.setStateInternal(LifecycleBase.java:423)
    at org.apache.catalina.util.LifecycleBase.setState(LifecycleBase.java:366)
    at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:893)
    at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:795)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1328)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1318)
    at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
    at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75)
    at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:140)
    at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:866)
    at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:249)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
    at org.apache.catalina.core.StandardService.startInternal(StandardService.java:428)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
    at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:923)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
    at org.apache.catalina.startup.Catalina.start(Catalina.java:772)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:347)
    at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:478)

28-Sep-2023 00:42:33.825 SEVERE [main] org.apache.catalina.core.StandardContext.startInternal Context [] startup failed due to previous errors

解决方案 #

错误根源是Tomcat启动时加载了旧版本Vaadin应用序列化的会话数据，新旧版本的com.vaadin.server.AbstractClientConnector类serialVersionUID不匹配，导致反序列化失败。需要清理以下两类数据：

1. 会话持久化文件 #

• 位置：Tomcat安装目录下的work/Catalina/localhost/[应用上下文路径]目录。如果是ROOT应用（直接通过域名访问的应用），路径为work/Catalina/localhost/ROOT。
• 操作：删除该目录下所有后缀为.ser的文件，这些是Tomcat持久化存储的会话序列化数据。

2. 临时部署文件 #

• 位置：
  • Tomcat根目录下的temp文件夹；
  • Tomcat的webapps目录中旧的应用包或解压后的目录（如果之前部署过同名应用）。
• 操作：
  • 删除temp目录下所有临时文件；
  • 确保webapps目录中仅保留最新的应用WAR包或解压后的目录，删除旧版本残留文件。

操作步骤 #

1. 先停止Tomcat服务；
2. 清理上述所有目标文件/目录；
3. 重新启动Tomcat并部署新应用。

内容的提问来源于stack exchange，提问作者Eljah