java 循环读取文件夹里面的文件

public ArrayList<String> list = new ArrayList<String>(0);//用arraylist保存扫描到的路径
public void Scan(String path) {
     File file = new File(path);
 File[] files = file.listFiles();
    String[] filenames = file.list();
   if (filenames == null)
              return;
     for (int i = 0; i < filenames.length; i++) {
             if (files[i].isFile()) {
                    if (files[i].getName().endsWith(“png”))//只获取带png结尾的文件
                               list.add(files[i].getPath());//获取路径
         } else if (files[i].isDirectory()) {
                        Scan(files[i].getPath());
           }
   }
}