Что не так?

public class Solution {
    public static void main(String[] args) throws IOException {
        File path = new File(args[0]);
        File resultFileAbsolutePath = new File(args[1]);
        PriorityQueue<File> fileNamesQueue = new PriorityQueue<>();
        PriorityQueue<File> filesQueue = new PriorityQueue<>();
        ArrayList<String> namesFileFinal = new ArrayList<>();
        File newFile = new File(path + "/"+"allFilesContent.txt");

        if(FileUtils.isExist(resultFileAbsolutePath)){
            FileUtils.renameFile(resultFileAbsolutePath, newFile);
        }

        Collections.addAll(filesQueue, path.listFiles());

        while (!filesQueue.isEmpty()){

            File currentFile = filesQueue.remove();
            if(!currentFile.isDirectory()){
               fileNamesQueue.add(currentFile);
            } else {
                Collections.addAll(filesQueue, currentFile.listFiles());
            }
        }

        for(File filesInDir : fileNamesQueue){
            if(filesInDir.length() <= 50){
                namesFileFinal.add(filesInDir.getAbsolutePath());
            }
        }

        OutputStream outputStream = new FileOutputStream(newFile);
        InputStream inputStream = null;
        for(String s : namesFileFinal){
            if(!s.equals(newFile.getName())){
                inputStream = new FileInputStream(s);
                while (inputStream.available() > 0){
                    outputStream.write(inputStream.read());
                }
                outputStream.write(("\n").getBytes());
            }


        }
        inputStream.close();
        outputStream.close();

    }
}