Android开发，写一段测试手机网络上传速度的代码

以下是一段测试手机网络上传速度的代码示例，使用了OkHttp库：

public class UploadSpeedTestActivity extends AppCompatActivity {

    private static final String UPLOAD_URL = "http://speedtest.ftp.otenet.gr/files/test100k.db";

    private ProgressBar progressBar;
    private TextView speedTextView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_upload_speed_test);

        progressBar = findViewById(R.id.progressBar);
        speedTextView = findViewById(R.id.speedTextView);

        new UploadTask().execute();
    }

    private class UploadTask extends AsyncTask<Void, Integer, Double> {

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            progressBar.setProgress(0);
            speedTextView.setText("");
        }

        @Override
        protected Double doInBackground(Void... voids) {
            OkHttpClient client = new OkHttpClient();
            RequestBody requestBody = new MultipartBody.Builder()
                    .setType(MultipartBody.FORM)
                    .addFormDataPart("file", "test", RequestBody.create(MediaType.parse("application/octet-stream"), new byte[1024 * 100]))
                    .build();
            Request request = new Request.Builder()
                    .url(UPLOAD_URL)
                    .post(requestBody)
                    .build();
            try {
                Response response = client.newCall(request).execute();
                long contentLength = response.body().contentLength();
                InputStream inputStream = response.body().byteStream();
                byte[] buffer = new byte[1024];
                long bytesUploaded = 0;
                int bytesRead;
                long startTime = System.currentTimeMillis();
                while ((bytesRead = inputStream.read(buffer)) != -1) {
                    bytesUploaded += bytesRead;
                    publishProgress((int) (bytesUploaded * 100 / contentLength));
                }
                inputStream.close();
                response.body().close();
                long endTime = System.currentTimeMillis();
                double timeElapsed = (endTime - startTime) / 1000.0;
                double speed = bytesUploaded / timeElapsed;
                return speed;
            } catch (IOException e) {
                e.printStackTrace();
            }
            return null;
        }

        @Override
        protected void onProgressUpdate(Integer... values) {
            super.onProgressUpdate(values);
            progressBar.setProgress(values[0]);
        }

        @Override
        protected void onPostExecute(Double speed) {
            super.onPostExecute(speed);
            if (speed != null) {
                String speedString = String.format(Locale.getDefault(), "%.2f KB/s", speed / 1024);
                speedTextView.setText(speedString);
            }
        }
    }
}

这段代码会向一个测试服务器上传一个100KB的文件，并计算上传速度，最后将速度显示在界面上。请注意，这个示例仅供参考，实际应用中需要根据具体情况进行调整。