Use Microsoft Cognitive Services Translate API in Android using Java

I recently implemented the MS Cognitive Services Translate API for Wordee. I switched to it after trying Google Translate API and I did that for two reasons:

1. Microsoft's API is better documented.
2. Google's API costs twice the MS's API.

Now, it was difficult to find a complete tutorial / example of how to implement the MS REST API in Android using Java, so I decided to share the first (and simplest, but flexible) version of that implementation.

The application I uploaded to illustrate the example consists of a Spinner to select the target language,  an EditText to enter the text you want to translate, a Button to perform the translation request and a TextView to show the translated text. The API automatically detects the source language.

This example is fully functional, you only need to provide a valid API key.

	public class MStranslate {
	private final static String API_KEY = "YOUR_API_KEY_HERE";
	private final static String TRANS_URL = "https://api.cognitive.microsofttranslator.com/translate?api-version=3.0&to=";
	private static final String TAG = MStranslate.class.getName();

view raw MStranslate_APIkey.java hosted with ❤ by GitHub

There are also two important things to clarify in this example. First, we saved the languages in a JSON file, that we have to retrieve and parse in order to populate the Spinner. Second, we have to perform the translation using an Async task, or we'll get a NetworkOnMainThreadException.

	private class TransAsynTask extends AsyncTask<String, Void, String>{
	@Override
	protected String doInBackground(String... strings) {
	MStranslate mStranslate = new MStranslate();
	String translationResult = mStranslate.performTrans(strings[0], strings[1]);
	return translationResult;
	}
	@Override
	protected void onPostExecute(String s) {
	transResult.setText("Translation: " + s);
	super.onPostExecute(s);
	}
	}

view raw MStranslate_asyncTask.java hosted with ❤ by GitHub

	private void loadJSON() {
	// get json resource file
	InputStream is = getResources().openRawResource(R.raw.languages_list);
	Scanner scanner = new Scanner(is);
	StringBuilder builder = new StringBuilder();
	while(scanner.hasNextLine()) {
	builder.append(scanner.nextLine());
	}
	parseJson(builder.toString());
	}
	private void parseJson(String s) {
	try {
	Gson gson = new Gson();
	languages = gson.fromJson(s,Map.class);
	// initialize spinner arraylist
	ArrayList<String> spinnerArray = new ArrayList<>();
	for (Object key : languages.keySet()) {
	// add each language to spinner's arraylist
	spinnerArray.add(key.toString());
	}
	// set up spinner
	spinnerAdapter = new ArrayAdapter<String>(this, R.layout.support_simple_spinner_dropdown_item, spinnerArray);
	spinner.setAdapter(spinnerAdapter);
	} catch (Exception e) {
	Log.e(TAG, e.getMessage());
	}

view raw MStranslate_langListJSON.java hosted with ❤ by GitHub

Do not forget to protect your API key and, of course, never upload it to public repositories.

Public repository on Github.