今天系統部署到新的測試機上面出現一個問題
org.apache.tomcat.util.bcel.classfile.ClassFormatException: Invalid byte tag in constant pool: 19
at org.apache.tomcat.util.bcel.classfile.Constant.readConstant(Constant.java:97)
at org.apache.tomcat.util.bcel.classfile.ConstantPool.<init>(ConstantPool.java:55)
at org.apache.tomcat.util.bcel.classfile.ClassParser.readConstantPool(ClassParser.java:176)
at org.apache.tomcat.util.bcel.classfile.ClassParser.parse(ClassParser.java:85)
at org.apache.catalina.startup.ContextConfig.processAnnotationsStream(ContextConfig.java:2042)
at org.apache.catalina.startup.ContextConfig.processAnnotationsJar(ContextConfig.java:1988)
at org.apache.catalina.startup.ContextConfig.processAnnotationsUrl(ContextConfig.java:1958)
at org.apache.catalina.startup.ContextConfig.processAnnotations(ContextConfig.java:1912)
at org.apache.catalina.startup.ContextConfig.webConfig(ContextConfig.java:1157)
at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:779)
at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:306)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:95)
at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5150)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:147)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:725)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:701)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:717)
at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1092)
at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1834)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
搜索了一下，有網友遇到過相似的情況，這個問題的原因是有些jar中增加了jdk9特性Module，Package信息，在這些包中可以找到module-info.class，其jdk版本號也對應1.9。比如我項目中受影響的jar是apiguardian-api-1.1.0.jar和stax-ex-1.8.jar，還有jaxb-runtime-2.3.1.jar等等，而這些包中其他的class文件版本號並沒有升級到1.9，而tomcat啓動時，會嘗試解析這些類，解析到module-info.class時，導致了報錯。
解決辦法是建議將tomcat升級到8.0最新版本，如8.5，9.0