private String[] getIndexFiles() throws IOException {
        String[] indexFiles = storeConfig.getIndexPath().list(new FilenameFilter() {
            @Override
            public boolean accept(File dir, String name) {
                return name.endsWith(".snapshot");
            }
        });

        if (indexFiles == null) {
            throw new IOException("can't list file in " + storeConfig.getIndexPath());
        }

        if (indexFiles.length == 0) {
            return null;
        }

        Arrays.sort(indexFiles, new Comparator<String>() {
            @Override
            public int compare(String left, String right) {
                return left.compareTo(right);
            }
        });

        return indexFiles;
    }
@author Robert HG (254963746@qq.com) on 12/19/15.
lts-core/src/main/java/com/github/ltsopensource/kv/index/MemIndexSnapshot.java