问如何使用okhttp进行本地测试

EN

File sdcard = Environment.getExternalStorageDirectory();
File testJson = new File(sdcard, "test.json");
HttpUtils.HttpGet(testJson., mCallback);

public class HttpUtils {
    private static final String TAG = "HttpUtils";

    private static final OkHttpClient mClient = new OkHttpClient();

    public static void HttpGet(String url, Callback callback) {
        //创建一个Request
        final Request request = new Request.Builder()
                .url(url)
                .build();
        //创建一个Call
        Call call = mClient.newCall(request);
        //请求加入调度
        call.enqueue(callback);
    }
}