添加以下代码来设置下载管理器的错误处理：

DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url));
DownloadManager downloadManager = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);

long downloadId = downloadManager.enqueue(request);

BroadcastReceiver receiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        if (DownloadManager.ACTION_DOWNLOAD_COMPLETE.equals(action)) {
            DownloadManager.Query query = new DownloadManager.Query();
            query.setFilterById(downloadId);
            Cursor cursor = downloadManager.query(query);
            if (cursor.moveToFirst()) {
                int columnIndex = cursor.getColumnIndex(DownloadManager.COLUMN_STATUS);
                int status = cursor.getInt(columnIndex);
                if (status == DownloadManager.STATUS_SUCCESSFUL) {
                    // File downloaded successfully
                } else if (status == DownloadManager.STATUS_FAILED) {
                    // Download failed, check error code
                    int errorCode = cursor.getInt(cursor.getColumnIndex(DownloadManager.COLUMN_REASON));
                    if (errorCode == DownloadManager.ERROR_CANNOT_RESUME
                            || errorCode == DownloadManager.ERROR_DEVICE_NOT_FOUND
                            || errorCode == DownloadManager.ERROR_FILE_ALREADY_EXISTS
                            || errorCode == DownloadManager.ERROR_FILE_ERROR
                            || errorCode == DownloadManager.ERROR_HTTP_DATA_ERROR
                            || errorCode == DownloadManager.ERROR_INSUFFICIENT_SPACE
                            || errorCode == DownloadManager.ERROR_TOO_MANY_REDIRECTS
                            || errorCode == DownloadManager.ERROR_UNHANDLED_HTTP_CODE
                            || errorCode == DownloadManager.ERROR_UNKNOWN) {
                        // Handle error
                    }
                }
            }
        }
    }
};

registerReceiver(receiver, new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE));