String result = null;

        InputStream resourceAsStream = null;
        if(servletContext != null){
            resourceAsStream = servletContext.getResourceAsStream(TEMPLATE_DIR + template);
        }else{
            try {
                resourceAsStream = new FileInputStream("template/"+template);
            } catch (FileNotFoundException ignored) {
            }
        }

        if(resourceAsStream == null){
            LOGGER.warn("Template "+template+" not found please create template before");
            return null;
        }
        try {
            String stringTemplate = IOUtils.toString(resourceAsStream);
            result = StrSubstitutor.replace(stringTemplate,params);
        } catch (IOException ignored) {
        }