java按时间顺序读取文件夹下的所有文件

/**
     * Getting files from Folder(Time Sorting by Modify time)
     * @param path
     * @return
     */
    private List<File> getFileSort(String path) {
 
        List<File> list = getFiles(path, new ArrayList<File>());
 
        if (list != null && list.size() > 0) {
 
            Collections.sort(list, new Comparator<File>() {
                public int compare(File file, File newFile) {
                    if (file.lastModified() < newFile.lastModified()) {
                        return 1;
                    } else if (file.lastModified() == newFile.lastModified()) {
                        return 0;
                    } else {
                        return -1;
                    }
 
                }
            });
 
        }
 
        return list;
    }
    
    /**
     * Get all the file from folders(img/{drivesid})
     *
     * @param realpath
     * @param files
     * @return
     */
    private List<File> getFiles(String realpath, List<File> files) {
 
        File realFile = new File(realpath);
        if (realFile.isDirectory()) {
            File[] subfiles = realFile.listFiles();
            for (File file : subfiles) {
                if (file.isDirectory()) {
                    getFiles(file.getAbsolutePath(), files);
                } else {
                    files.add(file);
                }
            }
        }
        return files;
    }