例如你要控制對ROOT目錄下文件的訪問：
首先更改$TOMCAT_HOME/ROOT/WEB-INF/web.xml
1。在<web-app>和</web-app>之間加入
  <security-constraint>
    <web-resource-collection>
      <web-resource-name>Entire Application</web-resource-name>
      <url-pattern>/*</url-pattern>
    </web-resource-collection>
    <auth-constraint>
       <!-- NOTE:  This role is not present in the default users file -->
       <role-name>user</role-name>
    </auth-constraint>
  </security-constraint>

  <!-- Define the Login Configuration for this Application -->
  <login-config>
    <auth-method>BASIC</auth-method>
    <realm-name>TEST ACCESS CONTROL</realm-name>
  </login-config>

2。然后在$TOMCAT_HOME/conf/tomcat-users.xml中加入
   <user name="user" password="password" roles="user"/>
   roles的名字和web.xml中的相對應(yīng)

在TOMCAT4.03中測試通過