class ClipboardService extends IntentService {
    private static String TAG = "ClipboardService";

    public ClipboardService() {
        super("ClipboardService");
    }

    /* Define service as sticky so that it stays in background */
    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        super.onStartCommand(intent, flags, startId);
        return START_STICKY;
    }

    @Override
    public void onCreate() {
        super.onCreate();
        // start itself to ensure our broadcast receiver is active
        Log.d(TAG, "Start clipboard service.");
        startService(new Intent(getApplicationContext(), ClipboardService.class));
    }

    /**
     * The IntentService calls this method from the default worker thread with
     * the intent that started the service. When this method returns, IntentService
     * stops the service, as appropriate.
     */
    @Override
    protected void onHandleIntent(Intent intent) {
    }
}

public class ClipperReceiver extends BroadcastReceiver {
    private static String TAG = "ClipboardReceiver";

    public static String ACTION_GET = "clipper.get";
    public static String ACTION_GET_SHORT = "get";
    public static String ACTION_SET = "clipper.set";
    public static String ACTION_SET_SHORT = "set";
    public static String EXTRA_TEXT = "text";

    public static boolean isActionGet(final String action) {
        return ACTION_GET.equals(action) || ACTION_GET_SHORT.equals(action);
    }

    public static boolean isActionSet(final String action) {
        return ACTION_SET.equals(action) || ACTION_SET_SHORT.equals(action);
    }

    @Override
    public void onReceive(Context context, Intent intent) {
        ClipboardManager cb = (ClipboardManager) context.getSystemService(Context.CLIPBOARD_SERVICE);
        if (isActionSet(intent.getAction())) {
            Log.d(TAG, "Setting text into clipboard");
            String text = intent.getStringExtra(EXTRA_TEXT);
            if (text != null) {
                cb.setText(text);
                setResultCode(Activity.RESULT_OK);
                setResultData("Text is copied into clipboard.");
            } else {
                setResultCode(Activity.RESULT_CANCELED);
                setResultData("No text is provided. Use -e text "text to be pasted"");
            }
        } else if (isActionGet(intent.getAction())) {
            Log.d(TAG, "Getting text from clipboard");
            CharSequence clip = cb.getText();
            if (clip != null) {
                Log.d(TAG, String.format("Clipboard text: %s", clip));
                setResultCode(Activity.RESULT_OK);
                setResultData(clip.toString());
            } else {
                setResultCode(Activity.RESULT_CANCELED);
                setResultData("");
            }
        }
    }
}

am broadcast -a clipper.set -e text "1-line text"

am broadcast -a clipper.set -e text "2-linentext"

am broadcast -a clipper.set -e text "2-linerntext"