原文见： http://blog.csdn.net/guochunyang/article/details/51820066
tomcat9.0 管理页面如：http://192.168.2.101:80/manager/html出现如下错误：
403 Access Denied
1.需要配置：
Tomcat/conf/tomcat-users.xml加入：
<role rolename="manager"/>
<role rolename="admin"/>
<role rolename="admin-gui"/>
<role rolename="manager-gui"/>
<user username="xxx" password="***" roles="admin-gui,manager-gui"/>
以上配置好后本地可以访问，http://127.0.0.1:8080/manager/html
2.另外，需要修改Tomcat/webapps/manager/META-INF/context.xml文件：
<Context antiResourceLocking="false" privileged="true" >
<!--
Remove the comment markers from around the Valve below to limit access to
the manager application to clients connecting from localhost
-->
<Valve className="org.apache.catalina.valves.RemoteAddrValve"
allow="127.d+.d+.d+|::1|0:0:0:0:0:0:0:1|d+.d+.d+.d+" />
-</Context>
或注释Value节点（tomcat9.0以下默认是注释的，所以不需修改）
<!--
<Valve className="org.apache.catalina.valves.RemoteAddrValve"
allow="127.d+.d+.d+|::1|0:0:0:0:0:0:0:1" />
-->
参考tomcat9.0文档：http://tomcat.apache.org/tomcat-9.0-doc/config/valve.html#Remote_Address_Filter