6、　　编写一个Java应用程序，文件名为Folder.java，编译后执行结果如下图所示，实现指定文件夹下目录和文件的文本形式的树状结构显示。要求：

1．　　输入： java Folder，显示当前文件夹下的目录和文件的文本形式树状显示；

2．　　输入： java Folder C:\test>，显示C:\test文件夹下的目录和文件的文本形式树状显示；（C:\test可以为任意文件夹路径名）

3．　　输入： java Folder add aa，在当前文件夹下面添加一个子目录（子目录名为：aa），同时显示当前文件夹下的最新目录和文件的文本形式树状显示；

4．　　输入： java Folder del aa，在当前文件夹下面删除一个子目录（子目录名为：aa），同时显示当前文件夹下的最新目录和文件的文本形式树状显示；（30分）

-6, write a Java application, file name Folder.java, compiled results of the implementation as shown below, to achieve the specified folders and files under the directory tree structure displayed in text form. Requirements:

1. Enter: java Folder, shows the current folder and files under the directory tree displayed in text form　

2. Enter: java Folder C: \ test>, shows C: \ test folder under the directory tree and display text files　(C: \ test folder path can be any name)

3. Enter: java Folder add aa, following in the current folder to add a subdirectory (subdirectory named: aa), also shows the current folder and files under the latest catalog tree display text form　

4. Enter: java Folder del aa, following in the current folder delete a subdirectory (subdirectory named: aa), also shows the current folder and files under the latest catalog tree display text form　(30 points)