Translate using Microsoft Translator Text API in Java (Japanese → English)

I have tried the Microsoft Translator text API in Java.

I couldn't find the Java sample source unexpectedly, so I will publish it as a reference. You can use it immediately if you change the key, tokenUrl, and transUrl according to your environment. By the way, you need to use your own key, which is as follows. tokenUrl (Token API for authentication-URL) https://api.cognitive.microsoft.com/sts/v1.0/issueToken
transUrl (API for translation-URL) https://api.microsofttranslator.com/V2/http.svc/TranslateArray

Source

@Component
public class TranslatorAPI {

    @Value("${translation.subscriptionKey}")
    private String key;

    @Value("${translation.tokenApi.url}")
    private String tokenUrl;

    @Value("${translation.transApi.url}")
    private String transUrl;

    /**
     *Translate the target character string into English.
     * @param words Target character
     * @return translation result
     */
    public String[] translator(String... words) {
        return translatorPOSTToEN(words);
    }

    /**
     *Get a token.
     */
    private String tokenPOST() {
        try (CloseableHttpClient httpClient = HttpClients.createDefault()) {
            HttpPost postMethod = new HttpPost(tokenUrl);

            // Header
            postMethod.setHeader("Content-Type", "application/json");
            postMethod.setHeader("Accept", "application/jwt");
            postMethod.setHeader("Ocp-Apim-Subscription-Key", key);

            try (CloseableHttpResponse response = httpClient.execute(postMethod)) {
                if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
                    HttpEntity entity = response.getEntity();
                    return EntityUtils.toString(entity, StandardCharsets.UTF_8);
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        }

        return null;
    }

    /**
     *Post to the translation API.
     */
    private String[] translatorPOSTToEN(String... words) {
        List<String> rtnWords = new ArrayList<String>();

        try (CloseableHttpClient httpClient = HttpClients.createDefault()) {

            HttpPost postMethod = new HttpPost(transUrl);

            // header
            //Get authentication token
            String token = tokenPOST();
            String authKey = "Bearer " + token;
            postMethod.setHeader("Content-Type", "application/xml");
            postMethod.setHeader("Authorization", authKey);

            //Translated word
            StringBuilder transWords = new StringBuilder();
            for (String word : words) {
                transWords.append("<string xmlns='http://schemas.microsoft.com/2003/10/Serialization/Arrays'>");
                transWords.append(word);
                transWords.append("</string>");
            }
            StringBuilder requestSB = new StringBuilder();
            requestSB.append("<TranslateArrayRequest>");
            requestSB.append("<AppId />");
            requestSB.append("<Texts>");
            requestSB.append(transWords.toString());
            requestSB.append("</Texts>");
            //Specify the language to be translated
            requestSB.append("<To>en</To>");
            requestSB.append("</TranslateArrayRequest>");

            postMethod.setEntity(new StringEntity(requestSB.toString(),
                    StandardCharsets.UTF_8));

            try (CloseableHttpResponse response = httpClient.execute(postMethod)) {
                if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
                    HttpEntity entity = response.getEntity();
                    String res = EntityUtils.toString(entity, StandardCharsets.UTF_8);
                    InputSource inputSource = new InputSource(new StringReader(res));
                    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
                    DocumentBuilder documentBuilder = factory.newDocumentBuilder();
                    Document document = documentBuilder.parse(inputSource);

                    //Sort the character string sentence to be translated
                    Element root = document.getDocumentElement();
                    NodeList rootChildren = root.getChildNodes();
                    for (int i = 0; i < rootChildren.getLength(); i++) {
                        Node node = rootChildren.item(i);
                        if (node.getNodeType() == Node.ELEMENT_NODE) {
                            Element element = (Element) node;
                            String val = element.getElementsByTagName("TranslatedText").item(0).getFirstChild().getNodeValue();
                            rtnWords.add(val);
                        }
                    }
                }
            }
        } catch (ParserConfigurationException | SAXException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        return rtnWords.toArray(new String[rtnWords.size()]);
    }

}

Verification

call

        //sample
        String[] words = tranApi.translator("this is a pen", "Apples are delicious");
        for (String word : words) {
            System.out.println(word);
        }

Output result

This is a pen.
Apple delicious