apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/util/RoleUtils.java/RoleUtils/extractAppIdFromRoleName
class RoleUtils:  public static String extractAppIdFromRoleName(String roleName) {
     Iterator<String> parts = STRING_SPLITTER.split(roleName).iterator();
     if (parts.hasNext()) {
       String roleType = parts.next();
       if (RoleType.isValidRoleType(roleType) && parts.hasNext()) {
         return parts.next();
       }
     }
     return null;
  }