Android 網絡框架 OKHttp3

概述

OKHttp是一個處理網絡請求的框架,其優勢有，支持http2，對一臺機器的全部請求共享同一個socket。

內置鏈接池，支持鏈接複用，減小延遲。經過緩存避免重複的請求，請求失敗時自動重試主機的其餘ip，自動重定向。 

添加依賴

compile 'com.squareup.okhttp3:okhttp:3.8.1'

Get請求

Get方式發送同步請求

OkHttpClient okHttpClient;
Request request;
okHttpClient = new OkHttpClient();
request = new Request.Builder()
        .url("http://www.baidu.com")//請求接口,若是須要傳參拼接到接口後面,如www.baidu.com?name=zhangsan&sex=18
        .build();
final Call call = okHttpClient.newCall(request);
new Thread(new Runnable() {
    @Override
    public void run() {
        try {
            Response response = call.execute();//獲得Response 對象
            if(response.isSuccessful()){//判斷是否響應
                Log.d("response ","響應碼"+response.code());//返回http協議的響應碼
                Log.d("response ","返回內容"+response.body().string());
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
});

Get方式發送異步請求

OkHttpClient okHttpClient;
Request request;
okHttpClient = new OkHttpClient();
request = new Request.Builder()
        .url("http://www.baidu.com")//請求接口。若是須要傳參拼接到接口後面，如www.baidu.com?name=zhangsan&sex=18
        .build();
final Call call = okHttpClient.newCall(request);
call.enqueue(new Callback() {
     @Override
     public void onFailure(Call call, IOException e) {

     }

     @Override
     public void onResponse(Call call, Response response) throws IOException {
            if(response.isSuccessful()){//判斷是否響應
                Log.d("response ","響應碼"+response.code());//返回http協議的響應碼
                Log.d("response ","返回內容"+response.body().string());
            }
     }
 });

Post請求

FormBody傳遞鍵值對參數

FormBody body = new FormBody.Builder() //建立信息主體
        .add("name", name)
        .add("sex", department)
        .add("possword", post)
        .add("data", formatter.format(getData()))
        .build();

RequestBody傳遞Json或File對象

//傳遞Json對象
MediaType JSON = MediaType.parse("application/json; charset=utf-8");//指定數據類型爲json對象，
String jsonStr = "{\"username\":\"lisi\",\"nickname\":\"李四\"}";//json數據.
RequestBody body = RequestBody.create(JSON, josnStr);

//傳遞File對象
MediaType fileType = MediaType.parse("File/*");//指定數據類型爲file對象，
File file = new File(path);//file對象
RequestBody body = RequestBody.create(fileType , file );

MultipartBody傳遞鍵值對對象和 File對象

MultipartBody multipartBody =new MultipartBody.Builder()
        .setType(MultipartBody.FORM)
        .addFormDataPart("groupId",""+Id)//添加鍵值對參數
        .addFormDataPart("file",file.getName(),RequestBody.create(MediaType.parse("file/*"), file))//添加文件
        .build();

Post同步/異步請求

//FormBody傳遞數據，Post同步請求
OkHttpClient okHttpClient;
okHttpClient = new OkHttpClient();
FormBody body = new FormBody.Builder() //建立信息主體
        .add("name", name)
        .add("sex", department)
        .add("possword", post)
        .add("data", formatter.format(getData()))
        .build();
Request requset = new Request.Builder()
        .url("url")
        .post(body)
        .build();
final Call call = okHttpClient.newCall(requset);
new Thread(new Runnable() {
    @Override
    public void run() {
        try {
            Response response = call3.execute();//獲得Response 對象
            if(response.isSuccessful()){//判斷是否響應
                Log.d("response ","響應碼"+response.code());//返回http協議的響應碼
                Log.d("response ","返回內容"+response.body().string());
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
});

//RequestBody()傳遞數據，Post異步請求
OkHttpClient okHttpClient;
okHttpClient = new OkHttpClient();
MediaType JSON = MediaType.parse("application/json; charset=utf-8");//數據類型爲json格式，
String jsonStr = "{\"username\":\"lisi\",\"nickname\":\"李四\"}";//json數據.
RequestBody body = RequestBody.create(JSON, jsonStr);
Request request = new Request.Builder()
        .url("http://www.baidu.com")
        .post(body)
        .build();
final Call call = okHttpClient.newCall(requset);
call.enqueue(new Callback() {
    @Override
    public void onFailure(Call call, IOException e) {

    }

    @Override
    public void onResponse(Call call, Response response) throws IOException {
        if(response.isSuccessful()){//判斷是否響應
            Log.d("response ","響應碼"+response.code());//返回http協議的響應碼
            Log.d("response ","返回內容"+response.body().string());
        }
    }
});

常規請求概述

經過上述代碼，Get或Post請求須要實例化OkHttpClient對象，用Request建立請求和Response發送請求，以及Call調度器接收返回內容。

Call對象有兩種模式，call.excute()同步模式，call.enqueue()異步模式。

同步是在主線程操做，因此須要開啓子線程操做。異步是CallBack回調回來的Response，是在子線程操做，可是回調的onFailure()和onResponse()依然在子線程中。

respinse.body() 也是在子線程，須要接收到內容，才能調用主線程操做。

注意response.body()只能調用一次，由於是輸出流的讀操做，而讀寫操做只接收一次，第二次會返回null。

設置網絡超時

OkHttpClient okHttpClient = new OkHttpClient.Builder()
    .connectTimeout(10, TimeUnit.SECONDS)//設置超時時間
    .readTimeout(10, TimeUnit.SECONDS)//設置讀取超時時間
    .writeTimeout(10, TimeUnit.SECONDS);//設置寫入超時時間

 OKHttp的攔截器

 轉載 — 關於OKHttp的攔截器

OKHttp下載文件

 轉載 — OKHttp下載文件實例