get server file system

Hi, there,

when I try to access a file on Server side from An Applet, I can use URL, for example, "http://1.1.1.1/some/some.gif", which has to be an exact file name. If I want to get the file system structure, for example, if I want to check how many files are in "http://1.1.1.1/some" directory, how can I do it?

When I try to use File class, it always gave me security warnning.

Help !!! Thanks in advance.

Yours Nicole

To see anything on the server requires that the server give it to you. For example when you use a URL or URLConnection, you are using the HTTP GET method to ask for the file. So if your server has a command that will return a list of files, use that. For example FTP has a command that will request the server to return a files list.

Thanks, dear,

I am still not clear about your comments. At present, I use IIS4.0 as web server.

Would you please send me some sample code,or give me other reference article. Thanks again.

yours Nicole

Hi, there,

When I wrote the following code in an Applet,


..................
URL url = new URL(getCodeBase()+"WorkInProgress/test1/");
File file = new File(url.toString());
File[] children = file.listFiles ();
..................




And when I run it in IE5, it always gives me the following error message:
---------------------------------
JAR cache enabled.

Opening http://64.16.6.114/ebiz/ADemo/testFile/testFile.class with cookie "ebizIntranet=USERID=Mark+Holman".

java.security.AccessControlException: access denied (java.io.FilePermission http:\64.16.6.114\ebiz\ADemo\WorkInProgress\test1 read)

at java.security.AccessControlContext.checkPermission(Unknown Source)

at java.security.AccessController.checkPermission(Unknown Source)

at java.lang.SecurityManager.checkPermission(Unknown Source)

at java.lang.SecurityManager.checkRead(Unknown Source)

at java.io.File.list(Unknown Source)

at java.io.File.listFiles(Unknown Source)

at testFile.testFile.jbInit(testFile.java:32)

at testFile.testFile.init(testFile.java:20)

at sun.applet.AppletPanel.run(Unknown Source)

at java.lang.Thread.run(Unknown Source)
-----------------------------------

But, if I call file.getParent() method, it works well in Browser, and shows the correct parent directory.

Would you please give me some instruction.
Thanks.

yours Nicole

The File class does Not read data from a server. It's only for local files. I don't think the use of the URL class in your code is correct. Your program is only reading data from the local computer.
To read anything from a server requires that the server be able to receive commands and respond to them. For example the FTP protocol has commands for the client to ask the server for a directory listing and many other file management commands such as deleting and renaming files. Each server can have different protocols that it responds to.

Thanks, Norm,

Would you please give me some sample to use Java access Server File System with FTP protocal? I don't know how to write this kind of code.

Thanks again.
yours Nicole

I'm sorry, I don't have a code sample using FTP. FTP is normally used manually from a DOS console. It's an old protocol that has been in use for a long time. The protocol is documented in a RFC, but I don't know the number. There has been another question on the forum about using FTP. It's not a simple 3 lines of code thing.

And not all servers have an FTP server.