Merhaba sevgili Android geli\u015ftiricileri! G\u00fcn\u00fcm\u00fcz mobil uygulamalar\u0131n\u0131n b\u00fcy\u00fck bir \u00e7o\u011funlu\u011fu, veri al\u0131\u015fveri\u015fi yapmak, kullan\u0131c\u0131 kimlik do\u011frulamas\u0131 sa\u011flamak veya dinamik i\u00e7erik sunmak i\u00e7in internet ba\u011flant\u0131s\u0131na ihtiya\u00e7 duyar. Bu a\u011f ileti\u015fimi s\u00fcre\u00e7lerini verimli, g\u00fcvenli ve kolay bir \u015fekilde y\u00f6netmek, uygulaman\u0131z\u0131n performans\u0131 ve kullan\u0131c\u0131 deneyimi a\u00e7\u0131s\u0131ndan kritik \u00f6neme sahiptir. \u0130\u015fte tam da bu noktada, Square taraf\u0131ndan geli\u015ftirilen ve Android ekosisteminde olduk\u00e7a pop\u00fcler olan OkHttp k\u00fct\u00fcphanesi devreye giriyor.<\/p>\n
Bu kapsaml\u0131 rehberde, OkHttp’nin ne oldu\u011funu, neden bu kadar tercih edildi\u011fini, temel ve geli\u015fmi\u015f kullan\u0131m senaryolar\u0131n\u0131, g\u00fcvenlik ve performans ipu\u00e7lar\u0131n\u0131 ve modern Android geli\u015ftirme yakla\u015f\u0131mlar\u0131yla nas\u0131l entegre edilece\u011fini detayl\u0131 bir \u015fekilde inceleyece\u011fiz. \u0130ster yeni ba\u015flayan bir geli\u015ftirici olun ister deneyimli bir profesyonel, bu makale OkHttp’yi uygulamalar\u0131n\u0131za entegre etmeniz ve a\u011f isteklerinizi ustal\u0131kla y\u00f6netmeniz i\u00e7in size yol g\u00f6sterecektir.<\/p>\n
OkHttp, Android ve Java uygulamalar\u0131 i\u00e7in tasarlanm\u0131\u015f, verimli bir HTTP istemcisidir. Modern a\u011f protokollerini (HTTP\/2, SPDY) destekler, ba\u011flant\u0131 havuzlama (connection pooling), GZIP s\u0131k\u0131\u015ft\u0131rma ve yan\u0131t \u00f6nbellekleme (response caching) gibi \u00f6zelliklerle performans\u0131 optimize eder. Google’\u0131n kendi k\u00fct\u00fcphanesi Volley’e k\u0131yasla daha d\u00fc\u015f\u00fck seviyeli ve esnek bir yap\u0131 sunarken, Retrofit gibi daha \u00fcst seviye k\u00fct\u00fcphanelerin temelinde de OkHttp yatar. Yani Retrofit kullan\u0131yor olsan\u0131z bile, asl\u0131nda arka planda OkHttp’nin g\u00fcc\u00fcnden faydalan\u0131rs\u0131n\u0131z.<\/p>\n
OkHttp’yi rakiplerinden ay\u0131ran ve geli\u015ftiriciler aras\u0131nda bu kadar pop\u00fcler olmas\u0131n\u0131 sa\u011flayan bir\u00e7ok \u00f6zellik bulunmaktad\u0131r:<\/p>\n
* Performans:<\/strong> OkHttp, ayn\u0131 ana bilgisayara yap\u0131lan tekrarlanan istekler i\u00e7in soketleri ve HTTP\/2 ak\u0131\u015flar\u0131n\u0131 yeniden kullanarak gecikmeyi azalt\u0131r. Ayr\u0131ca, b\u00fcy\u00fck yan\u0131tlar i\u00e7in GZIP s\u0131k\u0131\u015ft\u0131rmas\u0131n\u0131 otomatik olarak y\u00f6netir ve yan\u0131tlar\u0131 \u00f6nbelle\u011fe alarak a\u011f trafi\u011fini ve uygulama h\u0131z\u0131n\u0131 art\u0131r\u0131r. Android’de a\u011f ileti\u015fimi i\u00e7in kullan\u0131labilecek ba\u015fka se\u00e7enekler de mevcuttur. OkHttp’nin bu se\u00e7enekler aras\u0131ndaki yerini daha iyi anlamak i\u00e7in k\u0131sa bir kar\u015f\u0131la\u015ft\u0131rma yapal\u0131m:<\/p>\n * OkHttp’yi Android projenize entegre etmek ve kullanmaya ba\u015flamak olduk\u00e7a basittir. \u0130lk olarak, Gradle ba\u011f\u0131ml\u0131l\u0131klar\u0131n\u0131 eklememiz ve gerekli internet iznini vermemiz gerekiyor.<\/p>\n Ba\u011f\u0131ml\u0131l\u0131\u011f\u0131 ekledikten sonra projenizi senkronize edin.<\/p>\n Uygulaman\u0131z\u0131n internete eri\u015febilmesi i\u00e7in OkHttp ile bir GET iste\u011fi g\u00f6ndermek i\u00e7in \u00f6ncelikle bir \u00d6nemli Not:<\/strong> A\u011f istekleri, ana (UI) i\u015f par\u00e7ac\u0131\u011f\u0131nda (main thread) yap\u0131lmamal\u0131d\u0131r. Bu, uygulaman\u0131z\u0131n donmas\u0131na (ANR – Application Not Responding) neden olabilir. Bu nedenle, senkron istekler genellikle arka plan i\u015f par\u00e7ac\u0131klar\u0131nda (background threads) ger\u00e7ekle\u015ftirilir.<\/p>\n Yukar\u0131daki \u00f6rnekte, Android’de a\u011f istekleri i\u00e7in en yayg\u0131n ve \u00f6nerilen y\u00f6ntem asenkron yakla\u015f\u0131md\u0131r. OkHttp, Asenkron isteklerde, OkHttp’nin g\u00fcc\u00fc, sadece temel GET istekleriyle s\u0131n\u0131rl\u0131 de\u011fildir. POST istekleri, ba\u015fl\u0131k y\u00f6netimi, \u00f6nbellekleme ve interceptor’lar gibi geli\u015fmi\u015f \u00f6zellikler sayesinde karma\u015f\u0131k a\u011f senaryolar\u0131n\u0131 kolayca y\u00f6netebilirsiniz.<\/p>\n Veri g\u00f6ndermek i\u00e7in POST, PUT, DELETE gibi HTTP metodlar\u0131n\u0131 kullan\u0131r\u0131z. Bu metodlar genellikle bir istek g\u00f6vdesi (request body) i\u00e7erir. OkHttp, farkl\u0131 t\u00fcrde istek g\u00f6vdeleri olu\u015fturmak i\u00e7in JSON, API’lerle veri al\u0131\u015fveri\u015finde en yayg\u0131n kullan\u0131lan formatlardan biridir.<\/p>\n HTML formlar\u0131 gibi Dosya y\u00fcklemeleri i\u00e7in HTTP ba\u015fl\u0131klar\u0131, istemci ve sunucu aras\u0131nda ek bilgiler ta\u015f\u0131mak i\u00e7in kullan\u0131l\u0131r (\u00f6rne\u011fin, kimlik do\u011frulama token’lar\u0131, i\u00e7erik tipi).<\/p>\n * URL’e sorgu parametreleri eklemek i\u00e7in A\u011f isteklerinin belirli bir s\u00fcre i\u00e7inde tamamlanmas\u0131n\u0131 sa\u011flamak i\u00e7in zaman a\u015f\u0131mlar\u0131n\u0131 yap\u0131land\u0131rabilirsiniz. Bu, uygulaman\u0131z\u0131n uzun s\u00fcre donmas\u0131n\u0131 \u00f6nler.<\/p>\n OkHttp, yan\u0131tlar\u0131 disk \u00fczerinde \u00f6nbelle\u011fe alarak tekrarlanan isteklerde a\u011f trafi\u011fini azaltabilir ve yan\u0131t s\u00fcrelerini h\u0131zland\u0131rabilir.<\/p>\n Interceptor’lar, OkHttp’nin en g\u00fc\u00e7l\u00fc \u00f6zelliklerinden biridir. \u0130steklerin g\u00f6nderilmeden \u00f6nce veya yan\u0131tlar\u0131n al\u0131nmas\u0131ndan sonra m\u00fcdahale etmenizi sa\u011flar. Loglama, ba\u015fl\u0131k ekleme, hata i\u015fleme, yeniden deneme mekanizmalar\u0131 gibi bir\u00e7ok senaryoda kullan\u0131labilirler.<\/p>\n \u0130ki t\u00fcr interceptor vard\u0131r: Basit bir loglama interceptor \u00f6rne\u011fi:<\/p>\n Interceptor’\u0131 OkHttp kullan\u0131rken uygulaman\u0131z\u0131n g\u00fcvenli\u011fini ve performans\u0131n\u0131 art\u0131rmak i\u00e7in dikkat etmeniz gereken baz\u0131 \u00f6nemli noktalar \u015funlard\u0131r:<\/p>\n * HTTPS Kullan\u0131m\u0131:<\/strong> Her zaman HTTPS \u00fczerinden ileti\u015fim kurun. Bu, verilerin \u015fifrelenmesini ve man-in-the-middle sald\u0131r\u0131lar\u0131na kar\u015f\u0131 korunmas\u0131n\u0131 sa\u011flar. OkHttp, HTTPS’i varsay\u0131lan olarak destekler. Ancak sertifika sabitleme, sunucu sertifikalar\u0131 de\u011fi\u015fti\u011finde uygulaman\u0131z\u0131n \u00e7al\u0131\u015fmamas\u0131na neden olabilece\u011fi i\u00e7in dikkatli kullan\u0131lmal\u0131d\u0131r. Kotlin Coroutines, Android’de asenkron programlamay\u0131 basitle\u015ftirmek i\u00e7in harika bir ara\u00e7t\u0131r. OkHttp ile Coroutines’i birle\u015ftirmek, daha temiz ve okunabilir asenkron kod yazman\u0131z\u0131 sa\u011flar.<\/p>\n OkHttp’nin \u0130lk olarak, Gradle ba\u011f\u0131ml\u0131l\u0131klar\u0131n\u0131za Coroutines k\u00fct\u00fcphanesini ekleyin:<\/p>\n Ard\u0131ndan, OkHttp iste\u011fini Bu Bu yakla\u015f\u0131m, asenkron a\u011f isteklerini daha yap\u0131land\u0131r\u0131lm\u0131\u015f, hata y\u00f6netimi kolay ve okunabilir bir \u015fekilde yazman\u0131z\u0131 sa\u011flar.<\/p>\n OkHttp, Android uygulamalar\u0131nda a\u011f ileti\u015fimi i\u00e7in tart\u0131\u015fmas\u0131z en g\u00fc\u00e7l\u00fc ve esnek k\u00fct\u00fcphanelerden biridir. Performans optimizasyonlar\u0131, modern protokol deste\u011fi, zengin API’si ve interceptor’lar arac\u0131l\u0131\u011f\u0131yla sundu\u011fu geni\u015fletilebilirlik, onu her Android geli\u015ftiricisinin ara\u00e7 setinde bulunmas\u0131 gereken bir par\u00e7a haline getirir.<\/p>\n Bu rehberde, OkHttp’nin temel kurulumundan ba\u015flayarak GET ve POST istekleri, ba\u015fl\u0131k y\u00f6netimi, \u00f6nbellekleme, zaman a\u015f\u0131mlar\u0131 ve interceptor’lar gibi geli\u015fmi\u015f \u00f6zelliklerine kadar bir\u00e7ok konuyu ele ald\u0131k. Ayr\u0131ca, uygulaman\u0131z\u0131n g\u00fcvenli\u011fini ve performans\u0131n\u0131 art\u0131rmak i\u00e7in \u00f6nemli ipu\u00e7lar\u0131 verdik ve Kotlin Coroutines ile OkHttp’yi nas\u0131l entegre edece\u011finizi g\u00f6sterdik.<\/p>\n OkHttp’yi uygulamalar\u0131n\u0131za entegre ederek, daha h\u0131zl\u0131, daha g\u00fcvenilir ve daha y\u00f6netilebilir a\u011f i\u015flemleri sa\u011flayabilir, b\u00f6ylece kullan\u0131c\u0131lar\u0131n\u0131za daha iyi bir deneyim sunabilirsiniz. K\u00fct\u00fcphaneyi daha derinlemesine ke\u015ffetmek ve farkl\u0131 senaryolarda denemeler yapmak, OkHttp ustal\u0131\u011f\u0131n\u0131z\u0131 art\u0131racakt\u0131r. Ba\u015far\u0131lar dileriz!<\/body><\/p>\n","protected":false},"excerpt":{"rendered":"OkHttp ile Android Uygulamalar\u0131nda A\u011f \u0130stekleri Y\u00f6netimi: Kapsaml\u0131 Bir Rehber\nMerhaba sevgili Android geli\u015ftiricileri! G\u00fcn\u00fcm\u00fcz mobil uygulam","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"csco_page_header_type":"","csco_page_load_nextpost":"","csco_page_subscribe_form":"","csco_page_contact_form":"","footnotes":""},"categories":[1],"tags":[],"class_list":{"0":"post-37394","1":"post","2":"type-post","3":"status-publish","4":"format-standard","6":"category-genel","7":"cs-entry","8":"cs-video-wrap"},"yoast_head":"\n
\n* G\u00fcvenilirlik:<\/strong> Yayg\u0131n a\u011f sorunlar\u0131ndan (\u00f6rne\u011fin, ge\u00e7ici ba\u011flant\u0131 kesintileri) otomatik olarak kurtulma yetene\u011fine sahiptir. Ba\u011flant\u0131 sorunlar\u0131 ya\u015fand\u0131\u011f\u0131nda, iste\u011fi otomatik olarak yeniden dener veya farkl\u0131 bir IP adresi \u00fczerinden ba\u011flanmaya \u00e7al\u0131\u015f\u0131r.
\n* Modern Protokol Deste\u011fi:<\/strong> HTTP\/2 ve SPDY gibi modern a\u011f protokollerini destekleyerek tek bir ba\u011flant\u0131 \u00fczerinden birden fazla iste\u011fin paralel olarak g\u00f6nderilmesine olanak tan\u0131r, bu da performans\u0131 \u00f6nemli \u00f6l\u00e7\u00fcde art\u0131r\u0131r.
\n* Kullan\u0131m Kolayl\u0131\u011f\u0131 ve Esneklik:<\/strong> OkHttp’nin API’si olduk\u00e7a temiz ve anla\u015f\u0131l\u0131rd\u0131r. Hem senkron hem de asenkron istekler i\u00e7in basit ve tutarl\u0131 bir aray\u00fcz sunar. Ayr\u0131ca, interceptor’lar (arac\u0131lar) arac\u0131l\u0131\u011f\u0131yla istek ve yan\u0131t ya\u015fam d\u00f6ng\u00fcs\u00fcne m\u00fcdahale etme imkan\u0131 sunarak esnekli\u011fi maksimize eder.
\n* G\u00fcvenlik:<\/strong> HTTPS’i varsay\u0131lan olarak destekler ve sertifika sabitleme (certificate pinning) gibi geli\u015fmi\u015f g\u00fcvenlik \u00f6nlemleri sunar.<\/p>\nDi\u011fer K\u00fct\u00fcphanelerle Kar\u015f\u0131la\u015ft\u0131rma<\/h4>\n
HttpURLConnection<\/code>:<\/strong> Android’in yerle\u015fik a\u011f ileti\u015fim API’sidir. D\u00fc\u015f\u00fck seviyeli olmas\u0131 nedeniyle, bir istek g\u00f6ndermek ve yan\u0131t\u0131 i\u015flemek i\u00e7in daha fazla manuel kod yazmay\u0131 gerektirir. OkHttp, HttpURLConnection<\/code>‘\u0131n bir\u00e7ok eksikli\u011fini giderir ve modern API’ler sunar.
\n* Volley<\/code>:<\/strong> Google taraf\u0131ndan geli\u015ftirilen bir ba\u015fka a\u011f k\u00fct\u00fcphanesidir. \u00d6zellikle k\u00fc\u00e7\u00fck, s\u0131k a\u011f istekleri ve resim y\u00fcklemeleri i\u00e7in optimize edilmi\u015ftir. OkHttp kadar esnek de\u011fildir ve HTTP\/2 gibi modern protokolleri yerel olarak desteklemez.
\n* Retrofit<\/code>:<\/strong> Square taraf\u0131ndan geli\u015ftirilen ve OkHttp \u00fczerine in\u015fa edilmi\u015f bir REST istemcisidir. Deklaratif bir API sunarak RESTful servislerle \u00e7al\u0131\u015fmay\u0131 son derece kolayla\u015ft\u0131r\u0131r. Retrofit, a\u011f isteklerini tan\u0131mlamak i\u00e7in aray\u00fczleri ve anotasyonlar\u0131 kullan\u0131rken, bu istekleri ger\u00e7ekle\u015ftirmek i\u00e7in OkHttp’yi arka planda kullan\u0131r. Yani, OkHttp Retrofit’in “motoru” gibidir. Bu nedenle, OkHttp’yi \u00f6\u011frenmek, Retrofit’i daha iyi anlaman\u0131za ve gerekti\u011finde \u00f6zelle\u015ftirmenize yard\u0131mc\u0131 olacakt\u0131r.<\/p>\nOkHttp Kurulumu ve Temel Kullan\u0131m<\/h3>\n
Gradle Ba\u011f\u0131ml\u0131l\u0131klar\u0131<\/h4>\n
app\/build.gradle<\/code> dosyan\u0131za a\u015fa\u011f\u0131daki ba\u011f\u0131ml\u0131l\u0131\u011f\u0131 ekleyin. En g\u00fcncel OkHttp s\u00fcr\u00fcm\u00fcn\u00fc kullanmaya \u00f6zen g\u00f6sterin (genellikle 4.x.x<\/code> \u015feklindedir).<\/p>\ndependencies {\n \/\/ ... di\u011fer ba\u011f\u0131ml\u0131l\u0131klar\n implementation 'com.squareup.okhttp3:okhttp:4.12.0' \/\/ En g\u00fcncel s\u00fcr\u00fcm\u00fc kontrol edin\n}<\/code><\/pre>\n\u0130nternet \u0130zni<\/h4>\n
AndroidManifest.xml<\/code> dosyan\u0131za a\u015fa\u011f\u0131daki izni eklemeniz gerekmektedir:<\/p>\nTemel GET \u0130ste\u011fi (Senkron)<\/h4>\n
OkHttpClient<\/code> nesnesi olu\u015fturman\u0131z, ard\u0131ndan bir Request<\/code> nesnesi tan\u0131mlaman\u0131z ve son olarak bu iste\u011fi bir Call<\/code> nesnesi arac\u0131l\u0131\u011f\u0131yla y\u00fcr\u00fctmeniz gerekir.<\/p>\nimport okhttp3.OkHttpClient;\nimport okhttp3.Request;\nimport okhttp3.Response;\nimport java.io.IOException;\n\npublic class OkHttpExample {\n\n private final OkHttpClient client = new OkHttpClient();\n\n public void runSyncGetRequest(String url) {\n new Thread(() -> { \/\/ A\u011f iste\u011fini arka plan i\u015f par\u00e7ac\u0131\u011f\u0131nda \u00e7al\u0131\u015ft\u0131r\n Request request = new Request.Builder()\n .url(url)\n .build();\n\n try {\n Response response = client.newCall(request).execute();\n if (response.isSuccessful()) {\n String responseBody = response.body().string();\n System.out.println(\"Senkron Yan\u0131t: \" + responseBody);\n \/\/ UI g\u00fcncellemeleri i\u00e7in Handler veya runOnUiThread kullan\u0131n\n } else {\n System.err.println(\"Senkron \u0130stek Ba\u015far\u0131s\u0131z: \" + response.code());\n }\n } catch (IOException e) {\n System.err.println(\"Senkron \u0130stek Hatas\u0131: \" + e.getMessage());\n e.printStackTrace();\n } finally {\n \/\/ Kaynaklar\u0131 serbest b\u0131rakmak i\u00e7in response.body().close() \u00e7a\u011fr\u0131s\u0131 \u00f6nemlidir.\n \/\/ try-with-resources ile otomatik yap\u0131l\u0131r.\n }\n }).start();\n }\n\n public static void main(String[] args) {\n OkHttpExample example = new OkHttpExample();\n example.runSyncGetRequest(\"https:\/\/jsonplaceholder.typicode.com\/todos\/1\");\n }\n}<\/code><\/pre>\nrunSyncGetRequest<\/code> metodu bir Thread<\/code> i\u00e7inde \u00e7a\u011fr\u0131larak a\u011f i\u015fleminin ana i\u015f par\u00e7ac\u0131\u011f\u0131n\u0131 engellemesi engellenmi\u015ftir. Response.body().string()<\/code> metodu yan\u0131t g\u00f6vdesini String olarak d\u00f6nd\u00fcr\u00fcr. isSuccessful()<\/code> metodu HTTP 200-299 aral\u0131\u011f\u0131ndaki ba\u015far\u0131l\u0131 yan\u0131t kodlar\u0131n\u0131 kontrol eder.<\/p>\nTemel GET \u0130ste\u011fi (Asenkron)<\/h4>\n
enqueue()<\/code> metodu ve bir Callback<\/code> aray\u00fcz\u00fc ile asenkron istekleri kolayca y\u00f6netmenizi sa\u011flar. Callback<\/code> aray\u00fcz\u00fc, iste\u011fin ba\u015far\u0131l\u0131 bir \u015fekilde tamamland\u0131\u011f\u0131nda onResponse()<\/code> metodunu, bir hata olu\u015ftu\u011funda ise onFailure()<\/code> metodunu \u00e7a\u011f\u0131r\u0131r.<\/p>\nimport okhttp3.Call;\nimport okhttp3.Callback;\nimport okhttp3.OkHttpClient;\nimport okhttp3.Request;\nimport okhttp3.Response;\nimport java.io.IOException;\n\npublic class OkHttpAsyncExample {\n\n private final OkHttpClient client = new OkHttpClient();\n\n public void runAsyncGetRequest(String url) {\n Request request = new Request.Builder()\n .url(url)\n .build();\n\n client.newCall(request).enqueue(new Callback() {\n @Override\n public void onFailure(Call call, IOException e) {\n System.err.println(\"Asenkron \u0130stek Hatas\u0131: \" + e.getMessage());\n e.printStackTrace();\n \/\/ UI g\u00fcncellemeleri i\u00e7in:\n \/\/ runOnUiThread(() -> Toast.makeText(context, \"\u0130stek ba\u015far\u0131s\u0131z oldu!\", Toast.LENGTH_SHORT).show());\n }\n\n @Override\n public void onResponse(Call call, Response response) throws IOException {\n try (response) { \/\/ try-with-resources ile response otomatik kapat\u0131l\u0131r\n if (response.isSuccessful()) {\n String responseBody = response.body().string();\n System.out.println(\"Asenkron Yan\u0131t: \" + responseBody);\n \/\/ UI g\u00fcncellemeleri i\u00e7in:\n \/\/ runOnUiThread(() -> textView.setText(responseBody));\n } else {\n System.err.println(\"Asenkron \u0130stek Ba\u015far\u0131s\u0131z: \" + response.code() + \" - \" + response.message());\n }\n }\n }\n });\n }\n\n public static void main(String[] args) {\n OkHttpAsyncExample example = new OkHttpAsyncExample();\n example.runAsyncGetRequest(\"https:\/\/jsonplaceholder.typicode.com\/posts\/1\");\n }\n}<\/code><\/pre>\nonResponse<\/code> ve onFailure<\/code> metodlar\u0131 OkHttp’nin kendi arka plan i\u015f par\u00e7ac\u0131k havuzunda \u00e7a\u011fr\u0131l\u0131r. Bu nedenle, bu metodlar\u0131n i\u00e7inde do\u011frudan UI \u00f6\u011felerini g\u00fcncellemeye \u00e7al\u0131\u015f\u0131rsan\u0131z CalledFromWrongThreadException<\/code> hatas\u0131 al\u0131rs\u0131n\u0131z. UI g\u00fcncellemeleri i\u00e7in Activity.runOnUiThread()<\/code> metodunu veya bir Handler<\/code> kullanman\u0131z gerekir.<\/p>\nGeli\u015fmi\u015f OkHttp Kullan\u0131m Senaryolar\u0131<\/h3>\n
POST \u0130stekleri ve \u0130stek G\u00f6vdeleri (Request Body)<\/h4>\n
RequestBody<\/code> s\u0131n\u0131f\u0131n\u0131 ve t\u00fcrevlerini sunar.<\/p>\nJSON Verisi G\u00f6nderme<\/h5>\n
import okhttp3.MediaType;\nimport okhttp3.OkHttpClient;\nimport okhttp3.Request;\nimport okhttp3.RequestBody;\nimport okhttp3.Response;\nimport java.io.IOException;\n\npublic class OkHttpJsonPostExample {\n\n public static final MediaType JSON = MediaType.get(\"application\/json; charset=utf-8\");\n private final OkHttpClient client = new OkHttpClient();\n\n public void postJson(String url, String json) {\n RequestBody body = RequestBody.create(json, JSON);\n Request request = new Request.Builder()\n .url(url)\n .post(body)\n .build();\n\n client.newCall(request).enqueue(new Callback() {\n @Override\n public void onFailure(Call call, IOException e) {\n System.err.println(\"JSON POST Hatas\u0131: \" + e.getMessage());\n }\n\n @Override\n public void onResponse(Call call, Response response) throws IOException {\n try (response) {\n if (response.isSuccessful()) {\n System.out.println(\"JSON POST Ba\u015far\u0131l\u0131: \" + response.body().string());\n } else {\n System.err.println(\"JSON POST Ba\u015far\u0131s\u0131z: \" + response.code() + \" - \" + response.message());\n }\n }\n }\n });\n }\n\n public static void main(String[] args) {\n OkHttpJsonPostExample example = new OkHttpJsonPostExample();\n String jsonPayload = \"{\\\"title\\\": \\\"foo\\\", \\\"body\\\": \\\"bar\\\", \\\"userId\\\": 1}\";\n example.postJson(\"https:\/\/jsonplaceholder.typicode.com\/posts\", jsonPayload);\n }\n}<\/code><\/pre>\nForm Verisi G\u00f6nderme<\/h5>\n
application\/x-www-form-urlencoded<\/code> format\u0131nda veri g\u00f6ndermek i\u00e7in FormBody<\/code> s\u0131n\u0131f\u0131n\u0131 kullan\u0131r\u0131z.<\/p>\nimport okhttp3.FormBody;\nimport okhttp3.OkHttpClient;\nimport okhttp3.Request;\nimport okhttp3.RequestBody;\nimport okhttp3.Response;\nimport java.io.IOException;\n\npublic class OkHttpFormPostExample {\n\n private final OkHttpClient client = new OkHttpClient();\n\n public void postForm(String url, String param1, String param2) {\n RequestBody formBody = new FormBody.Builder()\n .add(\"key1\", param1)\n .add(\"key2\", param2)\n .build();\n\n Request request = new Request.Builder()\n .url(url)\n .post(formBody)\n .build();\n\n client.newCall(request).enqueue(new Callback() {\n @Override\n public void onFailure(Call call, IOException e) {\n System.err.println(\"Form POST Hatas\u0131: \" + e.getMessage());\n }\n\n @Override\n public void onResponse(Call call, Response response) throws IOException {\n try (response) {\n if (response.isSuccessful()) {\n System.out.println(\"Form POST Ba\u015far\u0131l\u0131: \" + response.body().string());\n } else {\n System.err.println(\"Form POST Ba\u015far\u0131s\u0131z: \" + response.code() + \" - \" + response.message());\n }\n }\n }\n });\n }\n\n public static void main(String[] args) {\n OkHttpFormPostExample example = new OkHttpFormPostExample();\n example.postForm(\"https:\/\/jsonplaceholder.typicode.com\/posts\", \"value1\", \"value2\");\n }\n}<\/code><\/pre>\nDosya Y\u00fckleme (MultipartBody)<\/h5>\n
multipart\/form-data<\/code> format\u0131 kullan\u0131l\u0131r. OkHttp, MultipartBody<\/code> s\u0131n\u0131f\u0131 ile bu t\u00fcr y\u00fcklemeleri kolayla\u015ft\u0131r\u0131r.<\/p>\nimport okhttp3.MediaType;\nimport okhttp3.MultipartBody;\nimport okhttp3.OkHttpClient;\nimport okhttp3.Request;\nimport okhttp3.RequestBody;\nimport okhttp3.Response;\nimport java.io.File;\nimport java.io.IOException;\n\npublic class OkHttpFileUploadExample {\n\n private final OkHttpClient client = new OkHttpClient();\n\n public void uploadFile(String url, File file, String fileName) {\n RequestBody requestBody = new MultipartBody.Builder()\n .setType(MultipartBody.FORM)\n .addFormDataPart(\"title\", \"OkHttp Dosya Y\u00fckleme\")\n .addFormDataPart(\"image\", fileName,\n RequestBody.create(file, MediaType.parse(\"image\/jpeg\"))) \/\/ Dosyan\u0131n MIME tipini belirtin\n .build();\n\n Request request = new Request.Builder()\n .url(url)\n .post(requestBody)\n .build();\n\n client.newCall(request).enqueue(new Callback() {\n @Override\n public void onFailure(Call call, IOException e) {\n System.err.println(\"Dosya Y\u00fckleme Hatas\u0131: \" + e.getMessage());\n }\n\n @Override\n public void onResponse(Call call, Response response) throws IOException {\n try (response) {\n if (response.isSuccessful()) {\n System.out.println(\"Dosya Y\u00fckleme Ba\u015far\u0131l\u0131: \" + response.body().string());\n } else {\n System.err.println(\"Dosya Y\u00fckleme Ba\u015far\u0131s\u0131z: \" + response.code() + \" - \" + response.message());\n }\n }\n }\n });\n }\n\n \/\/ Ger\u00e7ek bir dosya ile test etmek i\u00e7in:\n \/\/ public static void main(String[] args) {\n \/\/ OkHttpFileUploadExample example = new OkHttpFileUploadExample();\n \/\/ File dummyFile = new File(\"\/path\/to\/your\/image.jpg\"); \/\/ Ger\u00e7ek bir dosya yolu girin\n \/\/ if (dummyFile.exists()) {\n \/\/ example.uploadFile(\"https:\/\/api.example.com\/upload\", dummyFile, \"my_image.jpg\");\n \/\/ } else {\n \/\/ System.err.println(\"Dosya bulunamad\u0131: \" + dummyFile.getAbsolutePath());\n \/\/ }\n \/\/ }\n}<\/code><\/pre>\nBa\u015fl\u0131klar (Headers) Ekleme<\/h4>\n
Request request = new Request.Builder()\n .url(\"https:\/\/api.example.com\/data\")\n .header(\"Authorization\", \"Bearer YOUR_AUTH_TOKEN\") \/\/ Ba\u015fl\u0131k ekle\n .addHeader(\"User-Agent\", \"OkHttp Android App\") \/\/ Ba\u015fka bir ba\u015fl\u0131k ekle\n .build();<\/code><\/pre>\nheader(name, value)<\/code>: Belirtilen ba\u015fl\u0131\u011f\u0131 ekler veya mevcutsa g\u00fcnceller.
\n* addHeader(name, value)<\/code>: Belirtilen ba\u015fl\u0131\u011f\u0131 ekler. Ayn\u0131 isimde birden fazla ba\u015fl\u0131k eklemenize olanak tan\u0131r.
\n* removeHeader(name)<\/code>: Belirtilen isimdeki t\u00fcm ba\u015fl\u0131klar\u0131 kald\u0131r\u0131r.<\/p>\nSorgu Parametreleri (Query Parameters)<\/h4>\n
HttpUrl.Builder<\/code> kullanmak daha g\u00fcvenli ve okunakl\u0131d\u0131r, \u00f6zellikle parametreler \u00f6zel karakterler i\u00e7eriyorsa.<\/p>\nimport okhttp3.HttpUrl;\nimport okhttp3.OkHttpClient;\nimport okhttp3.Request;\nimport okhttp3.Response;\nimport java.io.IOException;\n\npublic class OkHttpQueryParamExample {\n\n private final OkHttpClient client = new OkHttpClient();\n\n public void getWithQueryParams(String baseUrl, String param1, String param2) {\n HttpUrl.Builder urlBuilder = HttpUrl.parse(baseUrl).newBuilder();\n urlBuilder.addQueryParameter(\"search\", param1);\n urlBuilder.addQueryParameter(\"filter\", param2);\n String url = urlBuilder.build().toString();\n\n Request request = new Request.Builder()\n .url(url)\n .build();\n\n client.newCall(request).enqueue(new Callback() {\n @Override\n public void onFailure(Call call, IOException e) {\n System.err.println(\"Sorgu Parametreli \u0130stek Hatas\u0131: \" + e.getMessage());\n }\n\n @Override\n public void onResponse(Call call, Response response) throws IOException {\n try (response) {\n if (response.isSuccessful()) {\n System.out.println(\"Sorgu Parametreli Yan\u0131t: \" + response.body().string());\n } else {\n System.err.println(\"Sorgu Parametreli \u0130stek Ba\u015far\u0131s\u0131z: \" + response.code() + \" - \" + response.message());\n }\n }\n }\n });\n }\n\n public static void main(String[] args) {\n OkHttpQueryParamExample example = new OkHttpQueryParamExample();\n example.getWithQueryParams(\"https:\/\/jsonplaceholder.typicode.com\/comments\", \"postid\", \"1\");\n }\n}<\/code><\/pre>\nZaman A\u015f\u0131mlar\u0131 (Timeouts)<\/h4>\n
import okhttp3.OkHttpClient;\nimport java.util.concurrent.TimeUnit;\n\nOkHttpClient client = new OkHttpClient.Builder()\n .connectTimeout(10, TimeUnit.SECONDS) \/\/ Ba\u011flant\u0131 zaman a\u015f\u0131m\u0131\n .readTimeout(30, TimeUnit.SECONDS) \/\/ Okuma zaman a\u015f\u0131m\u0131\n .writeTimeout(30, TimeUnit.SECONDS) \/\/ Yazma zaman a\u015f\u0131m\u0131\n .build();<\/code><\/pre>\n\u00d6nbellekleme (Caching)<\/h4>\n
import okhttp3.Cache;\nimport okhttp3.CacheControl;\nimport okhttp3.OkHttpClient;\nimport okhttp3.Request;\nimport okhttp3.Response;\nimport java.io.File;\nimport java.io.IOException;\nimport java.util.concurrent.TimeUnit;\n\npublic class OkHttpCachingExample {\n\n private OkHttpClient client;\n\n public OkHttpCachingExample(File cacheDir) {\n int cacheSize = 10 1024 <\/em> 1024; \/\/ 10 MB\n Cache cache = new Cache(cacheDir, cacheSize);\n\n client = new OkHttpClient.Builder()\n .cache(cache)\n .build();\n }\n\n public void getWithCache(String url) {\n Request request = new Request.Builder()\n .url(url)\n \/\/ \u0130ste\u011fin \u00f6nbellekleme davran\u0131\u015f\u0131n\u0131 kontrol et\n .cacheControl(new CacheControl.Builder()\n .maxAge(5, TimeUnit.MINUTES) \/\/ 5 dakika boyunca \u00f6nbellekten servis et\n .build())\n .build();\n\n client.newCall(request).enqueue(new Callback() {\n @Override\n public void onFailure(Call call, IOException e) {\n System.err.println(\"\u00d6nbellekleme Hatas\u0131: \" + e.getMessage());\n }\n\n @Override\n public void onResponse(Call call, Response response) throws IOException {\n try (response) {\n if (response.isSuccessful()) {\n System.out.println(\"\u00d6nbellekten mi geldi? \" + response.cacheResponse());\n System.out.println(\"A\u011fdan m\u0131 geldi? \" + response.networkResponse());\n System.out.println(\"\u00d6nbellekleme Yan\u0131t\u0131: \" + response.body().string());\n } else {\n System.err.println(\"\u00d6nbellekleme \u0130stek Ba\u015far\u0131s\u0131z: \" + response.code() + \" - \" + response.message());\n }\n }\n }\n });\n }\n\n \/\/ Android Context'i i\u00e7inde:\n \/\/ File cacheDirectory = new File(context.getCacheDir(), \"okhttp_cache\");\n \/\/ OkHttpCachingExample example = new OkHttpCachingExample(cacheDirectory);\n \/\/ example.getWithCache(\"https:\/\/publicobject.com\/helloworld.txt\");\n}<\/code><\/pre>\nCacheControl<\/code> ba\u015fl\u0131klar\u0131, hem istemci hem de sunucu taraf\u0131nda \u00f6nbellekleme stratejilerini belirlemek i\u00e7in kullan\u0131l\u0131r. max-age<\/code>, no-cache<\/code>, no-store<\/code> gibi direktiflerle \u00f6nbellekleme davran\u0131\u015f\u0131n\u0131 ince ayar yapabilirsiniz.<\/p>\nInterceptor’lar<\/h4>\n
\n* Uygulama Interceptor’lar\u0131 (addInterceptor()<\/code>):<\/strong> OkHttpClient<\/code>‘a eklenir ve t\u00fcm istekleri ve yan\u0131tlar\u0131 etkiler. \u0130stekleri ve yan\u0131tlar\u0131 de\u011fi\u015ftirebilir, yeniden y\u00f6nlendirebilir veya tamamen iptal edebilirler.
\n* A\u011f Interceptor’lar\u0131 (addNetworkInterceptor()<\/code>):<\/strong> Uygulama interceptor’lar\u0131ndan sonra, a\u011f \u00fczerinden veri g\u00f6nderilmeden hemen \u00f6nce ve al\u0131nd\u0131ktan hemen sonra \u00e7al\u0131\u015f\u0131r. A\u011f ba\u011flant\u0131s\u0131yla daha yak\u0131ndan ilgilidirler (\u00f6rne\u011fin, s\u0131k\u0131\u015ft\u0131r\u0131lm\u0131\u015f yan\u0131tlar\u0131 a\u00e7ma).<\/p>\nimport okhttp3.Interceptor;\nimport okhttp3.Response;\nimport java.io.IOException;\n\npublic class LoggingInterceptor implements Interceptor {\n @Override\n public Response intercept(Chain chain) throws IOException {\n Request request = chain.request();\n\n long t1 = System.nanoTime();\n System.out.println(String.format(\"G\u00f6nderiliyor %s %s on %s%n%s\",\n request.url(), request.method(), chain.connection(), request.headers()));\n\n Response response = chain.proceed(request);\n\n long t2 = System.nanoTime();\n System.out.println(String.format(\"Al\u0131nd\u0131 %s %s in %.1fms%n%s\",\n response.request().url(), response.code(), (t2 - t1) \/ 1e6d, response.headers()));\n\n return response;\n }\n}<\/code><\/pre>\nOkHttpClient<\/code>‘a ekleme:<\/p>\nOkHttpClient client = new OkHttpClient.Builder()\n .addInterceptor(new LoggingInterceptor()) \/\/ Uygulama interceptor'\u0131 ekle\n \/\/ .addNetworkInterceptor(new LoggingInterceptor()) \/\/ A\u011f interceptor'\u0131 ekle\n .build();<\/code><\/pre>\nG\u00fcvenlik ve Performans \u0130pu\u00e7lar\u0131<\/h3>\n
\n* Sertifika Sabitleme (Certificate Pinning):<\/strong> Ek bir g\u00fcvenlik katman\u0131 olarak sertifika sabitleme kullanabilirsiniz. Bu, uygulaman\u0131z\u0131n yaln\u0131zca belirli, \u00f6nceden tan\u0131mlanm\u0131\u015f sunucu sertifikalar\u0131na veya anahtarlar\u0131na g\u00fcvenmesini sa\u011flar. Bu, sahte sertifikalarla yap\u0131lan sald\u0131r\u0131lar\u0131 \u00f6nlemeye yard\u0131mc\u0131 olur.<\/p>\nimport okhttp3.CertificatePinner;\n import okhttp3.OkHttpClient;\n\n String hostname = \"publicobject.com\";\n OkHttpClient client = new OkHttpClient.Builder()\n .certificatePinner(new CertificatePinner.Builder()\n .add(hostname, \"sha256\/AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=\") \/\/ Ger\u00e7ek SHA256 hash'i ile de\u011fi\u015ftirin\n .build())\n .build();<\/code><\/pre>\n
\n* Arka Planda \u00c7al\u0131\u015fma:<\/strong> Daha \u00f6nce de belirtildi\u011fi gibi, t\u00fcm a\u011f i\u015flemlerini ana (UI) i\u015f par\u00e7ac\u0131\u011f\u0131ndan ayr\u0131 bir arka plan i\u015f par\u00e7ac\u0131\u011f\u0131nda ger\u00e7ekle\u015ftirin. Kotlin Coroutines, RxJava, AsyncTask<\/code> (Android 11’den itibaren kullan\u0131m\u0131 \u00f6nerilmez) veya ThreadPoolExecutor<\/code> gibi ara\u00e7lar\u0131 kullanabilirsiniz.
\n* Kaynaklar\u0131 Serbest B\u0131rakma:<\/strong> Response.body()<\/code>‘den al\u0131nan kaynaklar\u0131 (\u00f6rne\u011fin InputStream<\/code> veya Reader<\/code>) i\u015fledikten sonra mutlaka kapat\u0131n. try-with-resources<\/code> ifadesi bu konuda b\u00fcy\u00fck kolayl\u0131k sa\u011flar. Aksi takdirde bellek s\u0131z\u0131nt\u0131lar\u0131na neden olabilirsiniz.
\n* Singleton OkHttpClient:<\/strong> Her a\u011f iste\u011fi i\u00e7in yeni bir OkHttpClient<\/code> nesnesi olu\u015fturmaktan ka\u00e7\u0131n\u0131n. OkHttpClient<\/code>, ba\u011flant\u0131 havuzlama, \u00f6nbellekleme ve di\u011fer optimizasyonlar\u0131 y\u00f6netti\u011fi i\u00e7in uygulaman\u0131z\u0131n \u00f6mr\u00fc boyunca tek bir OkHttpClient<\/code> \u00f6rne\u011fi (singleton) kullanmak en iyi performans\u0131 sa\u011flar.
\n* Hata Y\u00f6netimi:<\/strong> A\u011f ba\u011flant\u0131s\u0131 sorunlar\u0131, sunucu hatalar\u0131 (4xx, 5xx), JSON ayr\u0131\u015ft\u0131rma hatalar\u0131 gibi olas\u0131 t\u00fcm hata senaryolar\u0131n\u0131 d\u00fczg\u00fcn bir \u015fekilde ele al\u0131n ve kullan\u0131c\u0131ya geri bildirim sa\u011flay\u0131n.<\/p>\nOkHttp ve Modern Android Geli\u015ftirme (Kotlin Coroutines ile Entegrasyon)<\/h3>\n
execute()<\/code> metodunu bir suspend<\/code> fonksiyon i\u00e7inde \u00e7a\u011f\u0131rarak ve Dispatchers.IO<\/code> kullanarak a\u011f i\u015flemini arka plan i\u015f par\u00e7ac\u0131\u011f\u0131nda g\u00fcvenli bir \u015fekilde ger\u00e7ekle\u015ftirebilirsiniz.<\/p>\ndependencies {\n \/\/ ...\n implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.7.1' \/\/ En g\u00fcncel s\u00fcr\u00fcm\u00fc kontrol edin\n}<\/code><\/pre>\nsuspend<\/code> bir fonksiyon i\u00e7inde nas\u0131l kullanaca\u011f\u0131n\u0131za dair bir \u00f6rnek:<\/p>\nimport kotlinx.coroutines.Dispatchers\nimport kotlinx.coroutines.withContext\nimport okhttp3.OkHttpClient\nimport okhttp3.Request\nimport okhttp3.Response\nimport java.io.IOException\n\nclass OkHttpCoroutineExample(private val client: OkHttpClient) {\n\n suspend fun fetchData(url: String): String {\n return withContext(Dispatchers.IO) { \/\/ A\u011f i\u015flemini IO i\u015f par\u00e7ac\u0131\u011f\u0131nda \u00e7al\u0131\u015ft\u0131r\n val request = Request.Builder()\n .url(url)\n .build()\n\n val response: Response = client.newCall(request).execute()\n if (response.isSuccessful) {\n response.body?.string() ?: throw IOException(\"Yan\u0131t g\u00f6vdesi bo\u015f\")\n } else {\n throw IOException(\"\u0130stek ba\u015far\u0131s\u0131z: ${response.code} - ${response.message}\")\n }\n }\n }\n}<\/code><\/pre>\nfetchData<\/code> fonksiyonunu bir ViewModel<\/code> veya ba\u015fka bir CoroutineScope<\/code> i\u00e7inde \u00e7a\u011f\u0131rabilirsiniz:<\/p>\nimport androidx.lifecycle.ViewModel\nimport androidx.lifecycle.viewModelScope\nimport kotlinx.coroutines.launch\nimport okhttp3.OkHttpClient\n\nclass MyViewModel : ViewModel() {\n private val okHttpClient = OkHttpClient() \/\/ Singleton olarak kullan\u0131lmal\u0131\n private val okHttpCoroutineExample = OkHttpCoroutineExample(okHttpClient)\n\n fun loadData() {\n viewModelScope.launch {\n try {\n val data = okHttpCoroutineExample.fetchData(\"https:\/\/jsonplaceholder.typicode.com\/todos\/1\")\n \/\/ UI'\u0131 g\u00fcncelle (\u00f6rne\u011fin, LiveData'ya de\u011fer atayarak)\n println(\"Veri y\u00fcklendi: $data\")\n } catch (e: IOException) {\n \/\/ Hata i\u015fleme\n println(\"Veri y\u00fcklenirken hata olu\u015ftu: ${e.message}\")\n }\n }\n }\n}<\/code><\/pre>\nSonu\u00e7<\/h3>\n