修改server.xml

vi $TOMCAT_HOME/conf/server.xml

<Host name="localhost"  appBase="webapps"
  unpackWARs="true" autoDeploy="true"
  xmlValidation="false" xmlNamespaceAware="false">
</Host>

#在</Host>前加入
<Context path="" docBase="projectName" debug="0" reloadable="true"/>

重启Tomcat服务