执行ADB Shell ScreenRecord的Java程序

Question

I want to create an app which executes adb shell screenrecord command on a button click.

i have already tried Runtime.getRuntime().exec() method, but it didn't work. I was first trying it on an emulator but i learned that screen record is not supported on emulators. Please let me know some solution ASAP.

Thanks in advance..

Answer 1

screenrecord need special permission with GID=graphics

Runtime.getRuntime().exec() will only set your child process' GID the same as yours. So you cannot record the screen with this approach.

Possible solution:

1. root your phone, and get a root shell first then tell it to execute screenrecord
2. start a background service process with adb shell, and use your app to control it

Answer 2

Here's a proof of concept that can be easily customized (time, location, bit-rate) to your needs:

private void record() {
  Log.d(getClass().getSimpleName(), "record()");

  final StringBuilder sbConsole = new StringBuilder();
  final StringBuilder sbErrors = new StringBuilder();

  AsyncTask<Void, Void, Void> recordTask = new AsyncTask<Void, Void, Void>() {
    @Override
    protected Void doInBackground(Void... objects) {
      Log.d(getClass().getSimpleName(), "recordTask.doInBackground()");

      DataOutputStream os = null;
      BufferedReader isReader = null;
      BufferedReader esReader = null;

      try {
        long start = System.currentTimeMillis();

        Process process = Runtime.getRuntime().exec("su");

        isReader = new BufferedReader(new InputStreamReader(process.getInputStream()));
        esReader = new BufferedReader(new InputStreamReader(process.getErrorStream()));

        os = new DataOutputStream(process.getOutputStream());
        os.writeBytes("screenrecord --verbose --time-limit 10 --bit-rate 6000000 /sdcard/demo_6m.mp4\n");
        // os.writeBytes("exit\n");
        os.flush();

        String line;
        while ((line = esReader.readLine()) != null) {
          sbErrors.append(line);
        }
        while ((line = isReader.readLine()) != null) {
          sbConsole.append(line);
        }

        process.waitFor();

        long end = System.currentTimeMillis();
        Log.d(getClass().getSimpleName(), "recordTask.doInBackground(); elapsed: "
            + (end - start) + " ms");

      } catch (IOException e) {
        Log.e(getClass().getSimpleName(), "Exception: ", e);
      } catch (InterruptedException e) {
        Log.e(getClass().getSimpleName(), "Exception: ", e);
      }

      return null;
    }

    @Override
    protected void onPostExecute(Void result) {
      Log.i(getClass().getSimpleName(), "Output: " + sbConsole.toString());
      Log.e(getClass().getSimpleName(), "Errors: " + sbErrors.toString());
    }
  };

  recordTask.execute();

}

Just call record() from onCreate() or invoke it via button click. Since the AsyncTask is detached from the app UI thread, it will record regardless if app is paused.

Nevertheless, the system can kill it at its convenience, so best approach is to control the actual recording from a service.

Answer 3

您需要成为Java中Process的超级用户，请参见我的示例： https : //github.com/adouggy/MyRecorder