Recursive invocation of executor: doesn't shut down after finishing Runnable

[kolesroma]

I pass the folder path to method iterateRecursive(String folderPath). If in folder there is another one, it creates a new Runnable and recusively invoce same method. The problem is when root Runnable finishes its work, the other Runnable may not finish yet

public class FileService {

    public void iterateRecursive(String folderPath) {
        File fileFolder = new File(folderPath);
        for (File file : fileFolder.listFiles()) {
            if (file.isDirectory()) {
                executor.submit(() -> iterateRecursive(file.getPath()));
            } else {
                findNotesAndSaveToFile(file.getPath());
            }
        }
        try {
            // problem is here
            // so I just wait a few seconds and then shut down an executor manually
            TimeUnit.SECONDS.sleep(5);
            executor.shutdown();
        } catch (InterruptedException e) {
            e.printStackTrace();
            throw new RuntimeException(e);
        }
    }

}