遇到一个问题记录下来，对以后在遇到的希望有帮助。
警告: Unable to load class [javax.xml.parsers.SecuritySupport12] to check against the @HandlesTypes annotation of one or more ServletContentInitializers.
java.lang.IllegalAccessError: class javax.xml.parsers.SecuritySupport12 cannot access its superclass javax.xml.parsers.SecuritySupport
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:791)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:2823)
at org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:1160)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1655)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1533)
at org.apache.catalina.startup.ContextConfig.checkHandlesTypes(ContextConfig.java:1988)
at org.apache.catalina.startup.ContextConfig.processAnnotationsStream(ContextConfig.java:1951)
at org.apache.catalina.startup.ContextConfig.processAnnotationsJar(ContextConfig.java:1840)
at org.apache.catalina.startup.ContextConfig.processAnnotationsUrl(ContextConfig.java:1808)
at org.apache.catalina.startup.ContextConfig.processAnnotations(ContextConfig.java:1794)
at org.apache.catalina.startup.ContextConfig.webConfig(ContextConfig.java:1214)
at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:828)
at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:302)
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:5148)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1525)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1515)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
at java.util.concurrent.FutureTask.run(FutureTask.java:166)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
at java.lang.Thread.run(Thread.java:722)
上网各种查啊，有的说少包的，有的说包可能重复有冲突的......
我用的rest框架，需要的包一个不多一个不少，也是从上一个项目中考过来的。现在可以启动tomcat服务，也没有错误。
但是我还需要引用公司内部几个jar包，问题就来了上面所报的错。
后来我改了下web.XML配置文件
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0" metadata-complete="true" >
在里面添加了metadata-complete="true" ok了。