#vulnerable code 
                             @Override
	public String getActionURL(FacesContext context, String viewId) {
		String actionURL = super.getActionURL(context, viewId);
		ServletContext servletContext = getServletContext(context);
		Map<String, String> mappedResources = getMappedResources(servletContext);

		if (mappedResources.containsKey(viewId) && (extensionless || isOriginalViewExtensionless(context))) {
			// User has requested to always render extensionless, or the requested viewId was mapped and the current
			// request is extensionless; render the action URL extensionless as well.

			String pathInfo = context.getViewRoot().getViewId().equals(viewId) ? coalesce(getRequestPathInfo(context), "") : "";

			if (mode == BUILD_WITH_PARENT_QUERY_PARAMETERS) {
				return getRequestContextPath(context) + stripExtension(viewId) + pathInfo + getQueryString(actionURL);
			}
			else {
				actionURL = removeExtension(servletContext, actionURL, viewId);
				return pathInfo.isEmpty() ? actionURL : (stripTrailingSlash(actionURL) + pathInfo + getQueryString(actionURL));
			}
		}

		// Not a resource we mapped or not a forwarded one, take the version from the parent view handler.
		return actionURL;
	} 
                            #location 18 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                             @Override
	public String getActionURL(FacesContext context, String viewId) {
		String actionURL = super.getActionURL(context, viewId);
		ServletContext servletContext = getServletContext(context);
		Map<String, String> mappedResources = getMappedResources(servletContext);

		if (mappedResources.containsKey(viewId) && (extensionless || isOriginalViewExtensionless(context))) {
			// User has requested to always render extensionless, or the requested viewId was mapped and the current
			// request is extensionless; render the action URL extensionless as well.

			String pathInfo = context.getViewRoot().getViewId().equals(viewId) ? coalesce(getRequestPathInfo(context), "") : "";
			String queryString = getQueryString(actionURL);

			if (mode == BUILD_WITH_PARENT_QUERY_PARAMETERS) {
				return getRequestContextPath(context) + stripExtension(viewId) + pathInfo + queryString;
			}
			else {
				actionURL = removeExtension(servletContext, actionURL, viewId);
				return (pathInfo.isEmpty() ? actionURL : (stripTrailingSlash(actionURL) + pathInfo)) + queryString;
			}
		}

		// Not a resource we mapped or not a forwarded one, take the version from the parent view handler.
		return actionURL;
	}