請求框架的類：

OkHttp依賴：

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

compile 'com.android.support:recyclerview-v7:26.0.0-alpha1'

public class OkHttpUtils {
    private Handler hand=new Handler();
    private NetDataCallback netDataCallback;
    public <T>void getdata(String url, final 
 
NetDataCallback netDataCallback, final Class<T> tclass) {
        //初始化一個 OkHttpClient 並且設定連線和讀取超時時間
OkHttpClient okhttp = new OkHttpClient.Builder()
                .connectTimeout(10, TimeUnit.SECONDS)
                .readTimeout(20, TimeUnit.SECONDS)
                .build();
        //構造一個Request物件
 
Request request = new Request.Builder().url(url).build();
        //通過request的物件去構造得到一個Call物件
Call call = okhttp.newCall(request);
        //呼叫的是call.enqueue，將call加入排程佇列，然後等待任務執行完成，我們在Callback中即可得到結果。
call.enqueue(new Callback() {
            //失敗的情況
@Override
public void onFailure(Call call, IOException e) {
                Log.e
 
("///////", "onFailure");
                netDataCallback.fail(499,e.getMessage());
            }
            //成功的情況
@Override
public void onResponse(Call call, Response response) throws IOException {
                Gson gson=new Gson();
                T t = gson.fromJson(response.body().string(), tclass);
                final Message msg = Message.obtain();
                msg.what=ok;
                msg.obj=t;
                hand.post(new Runnable() {
                    @Override
public void run() {
                        netDataCallback.success(msg.obj);
                    }
                });


            }
        });


    }
    //post請求
public <T>void getLoadDataPost(String url, final NetDataCallback netDataCallback, final Class<T> tClass, RequestBody body){
        this.netDataCallback=netDataCallback;
        OkHttpClient okHttpClient = new OkHttpClient.Builder()
                .readTimeout(20, TimeUnit.SECONDS)
                .connectTimeout(10, TimeUnit.SECONDS)
                .build();
        final Request request = new Request.Builder().url(url).post(body).build();
        Call call = okHttpClient.newCall(request);
        call.enqueue(new Callback() {
            @Override
public void onFailure(Call call, IOException e) {
                netDataCallback.fail(499,e.getMessage());
            }

            @Override
public void onResponse(Call call, Response response) throws IOException {
                T t = new Gson().fromJson(response.body().string(), tClass);
                final Message msg = Message.obtain();
                msg.what = OK;
                msg.obj = t;
               hand.post(new Runnable() {
                    @Override
public void run() {
                        netDataCallback.success(msg.obj);

                    }
                });
            }
        });
    }

}

定義一個介面：

public interface NetDataCallback<T> {
    void success(T t);
    void fail(int code,String str);
}