ora-24247：网络访问被访问控制列表(ACL)拒绝

用dba账户使用下面脚本授予报错账户访问外部网络服务的权限，以SCOTT为例：

 BEGIN

   -- Only uncomment the following line if ACL "network_services.xml" has already been created
   --DBMS_NETWORK_ACL_ADMIN.DROP_ACL('network_services.xml');

   DBMS_NETWORK_ACL_ADMIN.CREATE_ACL(
     acl => 'network_services.xml',
     description => 'NETWORK ACL',
     principal => 'SCOTT',
     is_grant => true,
     privilege => 'connect');

   DBMS_NETWORK_ACL_ADMIN.ADD_PRIVILEGE(
     acl => 'network_services.xml',
     principal => 'SCOTT',
     is_grant => true,
     privilege => 'resolve');

   DBMS_NETWORK_ACL_ADMIN.ASSIGN_ACL(
     acl => 'network_services.xml',
     host => '*');

   COMMIT;

 END;