我认为你可以使用这样recrusive功能：您可以通过这个例子帮助

I think that you can use recrusive function like this: you can take help through this example

public List<String> images=new ArrayList<String>();        

public recursiveFunction(File dirPath) {
    File f = new File(dirPath);
    File[] files = f.listFiles();

    for(int i=0;i,**files.length - 1**;i++)
    {
        if(files[position].isFile())
        {
          int mid= files[position].getName().lastIndexOf(".");
          String ext=files[position].getName().substring(mid+1,files[position].getName().length()); 

          if(   ext.equalsIgnoreCase("jpg")
             || ext.equalsIgnoreCase("png")
             || ext.equalsIgnoreCase("jpeg")
             || ext.equalsIgnoreCase("gif"))
          {
            images.add(files[position].getAbsoluteFile();
          }
        }
        else 
          recursiveFunction(files[position].getAbsoluteFile());
    }
  }

在图像列出你有你的所有图像。

in images list you have your all images.