Stands4AbbreviationExpansion.java 文件源码

/**Query the API and returns the list of expansions. Update the cache.
 * @param abbrev lowercase abbreviation.
 * @throws Exception
 */
private synchronized String[] queryApi(String abbrev, int retryLeft)
        throws Exception {
    if (retryLeft < MAX_RETRY)
        Thread.sleep(1000);
    URL url = new URL(String.format("%s?uid=%s&tokenid=%s&term=%s",
            API_URL, uid, tokenId, URLEncoder.encode(abbrev, "utf8")));

    boolean cached = abbrToExpansion.containsKey(abbrev);
    LOG.info("{} {}", cached ? "<cached>" : "Querying", url);
    if (cached) return abbrToExpansion.get(abbrev);


    HttpURLConnection connection = (HttpURLConnection) url
                .openConnection();
    connection.setConnectTimeout(0);
    connection.setRequestProperty("Accept", "*/*");
    connection
    .setRequestProperty("Content-Type", "multipart/form-data");

    connection.setUseCaches(false);

    if (connection.getResponseCode() != 200) {
        Scanner s = new Scanner(connection.getErrorStream())
                .useDelimiter("\\A");
        LOG.error("Got HTTP error {}. Message is: {}",
                connection.getResponseCode(), s.next());
        s.close();
        throw new RuntimeException("Got response code:"
                + connection.getResponseCode());
    }

    DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
    Document doc;
    try {
        doc = builder.parse(connection.getInputStream());
    } catch (IOException e) {
        LOG.error("Got error while querying: {}", url);
        throw e;
    }

    XPathFactory xPathfactory = XPathFactory.newInstance();
    XPath xpath = xPathfactory.newXPath();
    XPathExpression resourceExpr = xpath.compile("//definition/text()");

    NodeList resources = (NodeList) resourceExpr.evaluate(doc,
            XPathConstants.NODESET);

    Vector<String> resVect = new Vector<>();
    for (int i=0; i<resources.getLength(); i++){
        String expansion = resources.item(i).getTextContent().replace(String.valueOf((char) 160), " ").trim();
        if (!resVect.contains(expansion))
            resVect.add(expansion);
    }

    String[] res = resVect.toArray(new String[]{});
    abbrToExpansion.put(abbrev, res);
    increaseFlushCounter();
    return res;
}