jdk为1.8.0_45，tomcat 7.0.14。tomcat启动报错：org.apache.tomcat.util.bcel.classfile.ClassFormatException: Invalid byte tag in constant pool: 18
<span style="font-size:18px;">org.apache.tomcat.util.bcel.classfile.ClassFormatException: Invalid byte tag in constant pool: 18 at org.apache.tomcat.util.bcel.classfile.Constant.readConstant(Constant.java:131) 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:1930) at org.apache.catalina.startup.ContextConfig.processAnnotationsJar(ContextConfig.java:1826) at org.apache.catalina.startup.ContextConfig.processAnnotationsUrl(ContextConfig.java:1785) at org.apache.catalina.startup.ContextConfig.processAnnotations(ContextConfig.java:1771) at org.apache.catalina.startup.ContextConfig.webConfig(ContextConfig.java:1254) at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:881) at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:316) at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119) at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:89) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5103) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145) at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:812) at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:787) at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:607) at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:932) at org.apache.catalina.startup.HostConfig.deployWARs(HostConfig.java:723) at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:470) at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1322) at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:311) at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119) at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:89) at org.apache.catalina.util.LifecycleBase.setStateInternal(LifecycleBase.java:379) at org.apache.catalina.util.LifecycleBase.setState(LifecycleBase.java:324) at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1041) at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:774) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145) at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1033) at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:291) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145) at org.apache.catalina.core.StandardService.startInternal(StandardService.java:443) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145) at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:727) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145) at org.apache.catalina.startup.Catalina.start(Catalina.java:620) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:497) at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:303) at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:431) </span>
解决办法：
更换tomcat为8.5.20，就OK了。
但是为啥tomcat7.0就不行呢。网上找办法，果真有：
{tomcat路径}/conf/web.xml 修改方法:
<web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" metadata-complete="true">
metadata-complete="true" 这句话的意思是设置tomcat启动后不要自动扫描注解和网络碎片。
总结：
好记性不如烂笔头。
参考文章：
http://blog.csdn.net/dandandeshangni/article/details/50427322
