org.apache.catalina.core.StandardWrapperValve invoke報錯，standardwrappervalve

org.apache.catalina.core.StandardWrapperValve invoke報錯，standardwrappervalve

tomcat報錯如下：

HTTP Status 404 - Servlet xxx is not available

type Status report

message Servlet xxx is not available

description The requested resource is not available.

Apache Tomcat/6.0.37

org.apache.catalina.core.StandardWrapperValve invoke

INFO: Servlet xxx is currently unavailable