💌HTTP İstekleri

Android üzerinden HTTP istekleri, request ve response yapısı

🔰 HTTP İsteği Nedir?

• 🙏 Web sitelerinden içerik istemek için kullanılırlar

• 💫 API işlemlerinde sıklıkla kullanılırlar

• 🧱 GET, SET; POST vb. istek tipleri vardır

🆚 Volley ile Retrofit Farkı

📦 Volley	📦 Retrofit
Önbellek mekanizması	➖
Bağlantıyı tekrardan gönderme	➖
Gömülü olarak resim yüklenme desteği	➖
➖	JSON verilerini otomatik ayrıştırma

🌟 Volley Sık Kullanılanlar

🔤 String İstekleri

fun requestEarthQuakes(context: Context, onResponse: (String) -> Unit) {
        val queue = Volley.newRequestQueue(context)
        val stringRequest = StringRequest(Request.Method.GET, URL,
            Response.Listener<String> { response ->
                onResponse(response)
            },
            Response.ErrorListener { onResponse(null) }
        )

        queue.add(stringRequest)
    }

🖼️ Resim İndirme İstekleri

/**
 * Get [Bitmap] of image from the url
 */
fun requestImage(context: Context, onResponse: (Bitmap?) -> Unit) {
    val requestQueue = Volley.newRequestQueue(context)
    val imageRequest = ImageRequest(
        IMAGE_URL,
        Response.Listener { onResponse(it) },
        0, // Image width
        0, // Image height
        ImageView.ScaleType.CENTER_CROP, // Image scale type
        Bitmap.Config.RGB_565, //Image decode configuration
        Response.ErrorListener { onResponse(null) }
    )

    requestQueue.add(imageRequest)
}

📜 JSON İstekleri

/**
 * JSONArray Request
 */
fun requestJSONArray(
    context: Context,
    method: String,
    module: String,
    onResponse: (JSONArray?) -> Unit
) {
    val requestQueue = Volley.newRequestQueue(context)
    val jsonRequest = JsonArrayRequest(
        Request.Method.GET,
        "https://api.github.com/orgs/octokit/repos",
        null,
        Response.Listener { onResponse(it) },
        Response.ErrorListener {
            Log.e(TAG, "requestJSON: ", it)
            onResponse(null)
        }
    )

    requestQueue.add(jsonRequest)
}

⭐ Volley Örneği

*.java

/**
 * https://developer.android.com/training/volley/simple.html
 *
 * @return
 */
static void requestNewsData(Context context, ResponseListener responseListener) {

    RequestQueue queue = Volley.newRequestQueue(context);
    StringRequest stringRequest = new StringRequest(Request.Method.GET, MAIN_URL, (response) -> {
        // https://stackoverflow.com/a/9606629/9770490
        try {
            // new JSONObject(response).getJSONArray("articles").get(1).getString("source")
            JSONObject responseObject = new JSONObject(response);

            String status = responseObject.getString("status");
            if (status.equals("ok")) {
                JSONArray articles = new JSONObject(response).getJSONArray("articles");

                ArrayList<News> newsDataList = new ArrayList<>();
                for (int i = 0; i < articles.length(); i++) {
                    JSONObject article = articles.getJSONObject(i);
                    News news =  new News();

                    news.setTitle(article.getString("title"));
                    news.setDescription(article.getString("description"));
                    news.setUrlToImage(article.getString("urlToImage"));
                    news.setUrl(article.getString("url"));
                    news.setContent(article.getString("content"));
                    news.setSource(article.getJSONObject("source").getString("name"));
                    news.setPublishedAt(article.getString("publishedAt"));

                    newsDataList.add(news);

                    Log.i(TAG, "getNewsData: " + newsDataList.get(i));
                }

                responseListener.onResponse(newsDataList);
            }
        } catch (JSONException e) {
            e.printStackTrace();
        }
    }, Throwable::printStackTrace);

    queue.add(stringRequest);
}

interface ResponseListener {
    void onResponse(ArrayList<News> newsDataList);
}