登入Tomcat Manager时出现401错误——解决方法

要进入Tomcat Manager得先进行配置，进入tomcat解压目录->conf，对tomcat-users.xml进行修改。在这个文件中添加manager角色，并为管理员添加上这种角色即可

<?xml version='1.0' encoding='utf-8'?>

<tomcat-users>

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

</tomcat-users>

做了上面的改变如果还是有错误，请看下面：

<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"/>
 
  <user username="admin" password="admin" roles="manager"/>
  <user username="tomcat" password="tomcat" roles="tomcat"/>
  <user username="both" password="tomcat" roles="tomcat,role1"/>
  <user username="role1" password="tomcat" roles="role1"/>

-->

</tomcat-users>
把红色的线去掉就可以了，因为<!-->所包括的东西是要被忽略的，相当于注释的作用！

较高版本的使用admin-gui,不再是manager作为管理员权限

 <role rolename="admin-gui"/>

<user username="tomcat" password="tomcat" roles="tomcat,admin-gui"/>