Accessing the ftp server directories through the java program is not possible. Connection is established but reading the content is a problem. It works fine at root level.

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

class temp{

    public static void main(String args []) throws Exception {

// javasoft4.india is ftp server name

            String filename = "ftp://javasoft4.india" ; // works fine
            String filename = "ftp://javasoft4.india/" ;// works fine
            String filename = "ftp://javasoft4.india/pub" ;// gives error
            String filename = "ftp://javasoft4.india/etc" ;// gives error
            String filename = "ftp://javasoft4.india/usr" ;// gives error
            String filename = "ftp://javasoft4.india/dev" ;// gives error
            
            URL u = new URL(filename);

            System.err.println("URL: " + u);

            URLConnection uc = u.openConnection();

System.err.println("uc="+uc+"("+uc.getClass()+")");

            System.err.println(uc.getContentEncoding());

            System.err.println(uc.getContent());

            System.err.println("Content Length of File: " + uc.getContentLength());

            InputStream is = uc.getInputStream();

            int size = 0;
            int len = 0;
try{
            byte[] b = new byte[100];
            while ((len = is.read(b)) > 0) {
System.err.println("+"+len);
                size+=len;
            }


        } catch (Exception e) {
            e.printStackTrace();
        }

}
}
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ERROR generated
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"Error: sun.net.ftp.FtpProtocolException: PORT :501 PORT not
allowed after EPSV ALL"
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I have checked it with mantis jdk too. The problem is always reproducible.