報錯原因：
Caused by: java.lang.IllegalArgumentException: More than one fragment with the name [spring_web] was found. This is not legal with relative ordering. See section 8.2.2 2c of the Servlet specification for details. Consider using absolute ordering.
at org.apache.tomcat.util.descriptor.web.WebXml.orderWebFragments(WebXml.java:2260)
at org.apache.tomcat.util.descriptor.web.WebXml.orderWebFragments(WebXml.java:2218)
at org.apache.catalina.startup.ContextConfig.webConfig(ContextConfig.java:1133)
at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:774)
at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:301)
at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:123)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5056)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
... 27 more
<absolut解決辦法：
在web.xml加一個標籤：
