List<Info> getInfo(Map<String, Object> urlParamMap, HttpSession httpSession){
    HttpEntity<String> request = new HttpEntity<String>(httpSession.getHttpHeaders());
    restTemplate.setMessageConverters(httpSession.getMessageConverterList());

    ResponseEntity<JsonData> responseEntity = restTemplate.exchange("https://outsideOrg.com/{parameter}, HttpMethod.GET, request, JsonData.class, urlParamMap);

    List<Info> infoList = responseEntity.getBody().getInfoList();

    return infoList;
}

public class HttpSession {

    static Logger log = Logger.getLogger(HttpSession.class);

    private HttpHeaders httpHeaders;
    private List<HttpMessageConverter<?>> messageConverterList;

    HttpHeaders getHttpHeaders() {
        return httpHeaders;
    }

    void setHttpHeaders(HttpHeaders httpHeaders) {
        this.httpHeaders = httpHeaders;
    }

    List<HttpMessageConverter<?>> getMessageConverterList() {
        return messageConverterList;
    }

    void setMessageConverterList(List<HttpMessageConverter<?>> messageConverterList) {
        this.messageConverterList = messageConverterList;
    }

    void createHeaders(){
        HttpHeaders httpHeaders = new HttpHeaders();  
        try {
            File xmlFile = new File("C:/Users/User/docs/RestAuth.xml");
            DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
            DocumentBuilder documentBuilder = documentBuilderFactory.newDocumentBuilder();
            Document document = documentBuilder.parse(xmlFile);

            String username = document.getElementsByTagName("username").item(0).getTextContent();
            String password = document.getElementsByTagName("password").item(0).getTextContent(); 

            String authorization = username + ":" + password;
            byte[] encodedAuthorization = Base64.encodeBase64(authorization.getBytes(Charset.forName("US-ASCII")));   
            String authorizationHeader = "Basic " + new String(encodedAuthorization);

            httpHeaders.set("Authorization", authorizationHeader);
            httpHeaders.setAccept(Arrays.asList(MediaType.APPLICATION_JSON));

        }catch (ParserConfigurationException | SAXException | IOException e) {
            log.error("There was an error setting the credentials.", e);
        }
        this.httpHeaders = httpHeaders;
    }      

    void setupMessageConverters(){
        List<HttpMessageConverter<?>> messageConverterList = new ArrayList<>();
        MappingJackson2HttpMessageConverter messageConverter = new MappingJackson2HttpMessageConverter();
        ObjectMapper objectMapper = new ObjectMapper();
        objectMapper.enable(DeserializationFeature.ACCEPT_SINGLE_VALUE_AS_ARRAY, DeserializationFeature.ACCEPT_EMPTY_STRING_AS_NULL_OBJECT);
        messageConverter.setObjectMapper(objectMapper);
        messageConverterList.add(messageConverter);

        this.messageConverterList = messageConverterList;
    }