public List<AbstractFile> loadExistedFiles() {
        final File dir = new File(this.storePath);
        if(!dir.exists()) {
            dir.mkdirs();
        }
        final File[] files = dir.listFiles();
        if (files == null || files.length == 0) {
            return Collections.emptyList();
        }
        Arrays.sort(files, Comparator.comparing(this::getFileSequenceFromFileName));
        final List<AbstractFile> blankFiles = new ArrayList<>(files.length);
        long nextFileSequence = 0;
        for (final File file : files) {
            AbstractFile abstractFile;
            if ((abstractFile = checkFileCorrectnessAndMmap(file)) != null) {
                if (abstractFile.loadHeader() && !abstractFile.isBlank()) {
                    this.files.add(abstractFile);
                } else {
                    abstractFile.reset();
                    blankFiles.add(abstractFile);
                }
                nextFileSequence = Math.max(nextFileSequence, getFileSequenceFromFileName(file) + 1);
            }
        }
        this.allocateService.setNextFileSequence(nextFileSequence);
        // Add blank files to allocator so that we can reuse them
        this.allocateService.addBlankAbstractFiles(blankFiles);
        return this.files;
    }
Load abstract files that existed in this store path
This function will be called when db recover
@return the existed files list
jraft-extension/java-log-storage-impl/src/main/java/com/alipay/sofa/jraft/storage/file/FileManager.java