Tomcat7 进入管理界面的方法，401 错误解决方法

原博客文章备份：https://blog.csdn.net/leofitz/article/details/79886706
按照网上各种教程，取消注释等等方法，总是输入三次用户和密码后显示 401 错误，只有按下面代码更改后能进入

<tomcat-users>
<!--
  NOTE:  By default, no user is included in the "manager-gui" role required
  to operate the "/manager/html" web application.  If you wish to use this app,
  you must define such a user - the username and password are arbitrary.
-->
<!--
  NOTE:  The sample user and role entries below are wrapped in a comment
  and thus are ignored when reading this file. Do not forget to remove
  <!.. ..> that surrounds them.
-->

  <role rolename="tomcat"/>
  <role rolename="role1"/>
  <role rolename="manager-gui"/>
  <user username="tomcat" password="tomcat" roles="tomcat,manager-gui"/>
  <user username="both" password="tomcat" roles="tomcat,role1"/>
  <user username="role1" password="tomcat" roles="role1"/>

</tomcat-users>