begin
DBMS_NETWORK_ACL_ADMIN.CREATE_ACL (
    acl          => 'www.xml', --access control list file name (.xml)
    description  => 'Permissions to access tomcat',
    principal    => 'SYSTEM', --replace with the DDM user
    is_grant     => TRUE,
    privilege    => 'connect');
   COMMIT;
     
   
   DBMS_NETWORK_ACL_ADMIN.ASSIGN_ACL (
    acl          => ‘www.xml',   --the file name you gave in the precedent command              
    host         => '*'); --which host is available for the access control
   COMMIT; 
End ;