/** Looks up the local database, creating if necessary. */
  private DataSource findDatabaseImpl(String url, String driverName) throws SQLException {
    try {
      synchronized (_databaseMap) {
        DBPool db = _databaseMap.get(url);

        if (db == null) {
          db = new DBPool();

          db.setVar(url + "-" + _gId++);

          DriverConfig driver = db.createDriver();

          ClassLoader loader = Thread.currentThread().getContextClassLoader();

          Class driverClass = Class.forName(driverName, false, loader);

          driver.setType(driverClass);
          driver.setURL(url);

          db.init();

          _databaseMap.put(url, db);
        }

        return db;
      }
    } catch (RuntimeException e) {
      throw e;
    } catch (SQLException e) {
      throw e;
    } catch (Exception e) {
      throw ConfigException.create(e);
    }
  }
  /**
   * Returns true if the user represented by the current request plays the named role.
   *
   * @param role the named role to test.
   * @return true if the user plays the role.
   */
  public boolean isUserInRole(String role) {
    ServletInvocation invocation = getInvocation();

    if (invocation == null) {
      if (getRequest() != null) return getRequest().isUserInRole(role);
      else return false;
    }

    HashMap<String, String> roleMap = invocation.getSecurityRoleMap();

    if (roleMap != null) {
      String linkRole = roleMap.get(role);

      if (linkRole != null) role = linkRole;
    }

    String runAs = getRunAs();

    if (runAs != null) return runAs.equals(role);

    WebApp webApp = getWebApp();

    Principal user = getUserPrincipal();

    if (user == null) {
      if (log.isLoggable(Level.FINE)) log.fine(this + " no user for isUserInRole");

      return false;
    }

    RoleMapManager roleManager = webApp != null ? webApp.getRoleMapManager() : null;

    if (roleManager != null) {
      Boolean result = roleManager.isUserInRole(role, user);

      if (result != null) {
        if (log.isLoggable(Level.FINE)) log.fine(this + " userInRole(" + role + ")->" + result);

        return result;
      }
    }

    Login login = webApp == null ? null : webApp.getLogin();

    boolean inRole = login != null && login.isUserInRole(user, role);

    if (log.isLoggable(Level.FINE)) {
      if (login == null) log.fine(this + " no Login for isUserInRole");
      else if (user == null) log.fine(this + " no user for isUserInRole");
      else if (inRole) log.fine(this + " " + user + " is in role: " + role);
      else log.fine(this + " failed " + user + " in role: " + role);
    }

    return inRole;
  }