Apache ActiveMQ 启动报错
Apache ActiveMQ 5.5.0 启动时报如下错：

Caused by: java.lang.LinkageError: JAXB 2.0 API is being loaded from the bootstap classloader, but this RI (from jar:file:/D:/develop/activemq/apache-activemq 5.3.0/bin/../lib/jaxb-impl-2.1.6.jar!/com/sun/xml/bind/v2/model/impl/ModelBuild r.class) needs 2.1 API. Use the endorsed directory mechanism to place jaxb-api. ar in the bootstrap classloader. (See http://java.sun.com/j2se/1.5.0/docs/guidestandards/) 

经查询资料是jar包版本冲突所致，jdk自带2.0API，而ActiveMQ的lib包下有个2.1API，所以启动时冲突。
去掉ActiveMQ下的jaxb-impl-2.1.6.jar包后不再报错。