import java.net.*;
import java.io.*;
import java.util.*;


/**
* Shows the size of a file system directory/folder.
*/
public class FolderSize
{
public static void main(String args[]) throws Exception
{
if (args.length < 1)
{
System.err.println("usage: java FolderSize StartFolderName");
System.exit(1);
}

System.out.println("Size = " + getFolderSize(new File(args[0])));
}


public static long getFolderSize(File folder)
throws IllegalArgumentException
{
// Validate
if (folder == null ¦¦ !folder.isDirectory())
throw new IllegalArgumentException("Invalid folder");

String list[] = folder.list();
if (list == null ¦¦ list.length < 1)
return 0;


// Get size
File object = null;
long folderSize = 0;

for (int i=0; i < list.length; i++)
{
object = new File(folder, list[i]);
if (object.isDirectory())
folderSize += getFolderSize(object);
else
if (object.isFile())
folderSize += object.length();
}


return folderSize;
}
}

You'll probably have to get a list of files in the directory, and add up their sizes. Since the "size" of a directory means different things on different platforms, my guess is that the return value of File.length for directories is useless (like 0 or -1 something).

-chris

Does java.io.File.length() not work then?

Dermot