org.apache.tomcat.util.bcel.classfile.ClassFormatException: Invalid byte tag in constant pool: 19
tomcat启动红色警告，虽然没影响项目启动运行，但是看着很不爽啊，得搞一波。
严重: Unable to process Jar entry [module-info.class] from Jar [jar:file:/D:/maven/repository/com/fasterxml/jackson/core/jackson-annotations/2.12.3/jackson-annotations-2.12.3.jar!/] for annotations 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:133) at org.apache.tomcat.util.bcel.classfile.ConstantPool.<init>(ConstantPool.java:60) at org.apache.tomcat.util.bcel.classfile.ClassParser.readConstantPool(ClassParser.java:209) at org.apache.tomcat.util.bcel.classfile.ClassParser.parse(ClassParser.java:119) at org.apache.catalina.startup.ContextConfig.processAnnotationsStream(ContextConfig.java:2134) at org.apache.catalina.startup.ContextConfig.processAnnotationsJar(ContextConfig.java:2010) at org.apache.catalina.startup.ContextConfig.processAnnotationsUrl(ContextConfig.java:1976) at org.apache.catalina.startup.ContextConfig.processAnnotations(ContextConfig.java:1961) at org.apache.catalina.startup.ContextConfig.webConfig(ContextConfig.java:1319) at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:878) at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:376) 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:5322) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549) at java.util.concurrent.FutureTask.run$$$capture(FutureTask.java:266) at java.util.concurrent.FutureTask.run(FutureTask.java) 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)
在jackson-annotations-2.12.3.jar这个jar中有一个module-info.class无法处理。
重点是：Invalid byte tag in constant pool: 19
翻译一下：无效字节标签在常量池:19
这句话是说这个类有用到java9中的新特性，而项目本身是使用的java8。
在idea中双击shift搜索module-info.class如图：
可以看出来这个类确实使用了java9。
解决办法：将maven中jackson-annotations-2.12.3.jar的引用降低版本即可。
