[Bug libgcj/27163] New: FTP directory listing doesn't work

[Bug libgcj/27163] New: FTP directory listing doesn't work

[r_ovidius at eml dot cc]

GCJ 4.1.0

The following prints the ftp directory list when using Sun's java.  With gcj it
does not.  

(The first url (microsoft) prints nothing, the second (gcc.gnu.org) results in

gnu.java.net.protocol.ftp.FTPException: Invalid number of arguments.
   at gnu.java.net.protocol.ftp.FTPConnection.changeWorkingDirectory
(libgcj.so.7)
   at gnu.java.net.protocol.ftp.FTPURLConnection.getInputStream (libgcj.so.7)
   at java.net.URL.openStream (libgcj.so.7)
   at Ftest.main (Ftest)

)


---

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

public class Ftest {

 public static void main(String[] args) {
    String url = "ftp://ftp.microsoft.com/ResKit/y2kfix/";
    // String url = ftp://gcc.gnu.org/";

    try {
      InputStream input = (new URL(url)).openStream();
      BufferedReader file = new BufferedReader(new InputStreamReader(input));
      System.err.println("START");
      while (file.ready()) {
        String line = file.readLine();
        System.err.println(">" + line + "<");
      }
      System.err.println("DONE");

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

  }

}


-- 
           Summary: FTP directory listing doesn't work
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libgcj
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: r_ovidius at eml dot cc


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27163

[Bug classpath/27163] FTP directory listing doesn't work

[tromey at gcc dot gnu dot org]

------- Comment #1 from tromey at gcc dot gnu dot org  2006-04-19 18:39 -------
I spent some time looking into this bug today.
I am not certain that it is a bug, but I'm also not convinced
that it isn't.

I tracked it down to the ftp data socket's available() method
returning 0.  This causes the 'file.ready()' condition on the loop
to return false.

The test case does work for me on occasion... if the timing is right,
data will be available on the socket for reading, and the ready() test
will succeed.

If this is a bug it is a rather obscure one, as in, perhaps the ftp
code should ensure that some bytes are available before returning the
input stream.  

It is probably more usual for loops like this to simply call
readLine and then break out if it returns null.  When I change the
test case to do this, it works all the time.

I only see the exception with gij 4.1 (not trunk) and the gcc.gnu.org site.
I haven't looked into this yet.


-- 

tromey at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |tromey at gcc dot gnu dot
                   |                            |org
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2006-04-19 18:39:12
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27163

[Bug classpath/27163] FTP directory listing doesn't work

[tromey at gcc dot gnu dot org]

------- Comment #2 from tromey at gcc dot gnu dot org  2006-04-19 18:56 -------
Subject: Bug 27163

Author: tromey
Date: Wed Apr 19 18:56:10 2006
New Revision: 113091

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=113091
Log:
        PR classpath/27163:
        * gnu/java/net/protocol/ftp/ActiveModeDTP.java: Replaced with
        latest classpath version.
        * gnu/java/net/protocol/ftp/FTPURLConnection.java: Likewise.

Modified:
    branches/gcc-4_1-branch/libjava/classpath/ChangeLog.gcj
   
branches/gcc-4_1-branch/libjava/classpath/gnu/java/net/protocol/ftp/ActiveModeDTP.java
   
branches/gcc-4_1-branch/libjava/classpath/gnu/java/net/protocol/ftp/FTPURLConnection.java


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27163

[Bug classpath/27163] FTP directory listing doesn't work

[r_ovidius at eml dot cc]

------- Comment #3 from r_ovidius at eml dot cc  2006-04-20 17:20 -------
Try with 

String url = "ftp://gcc.gnu.org";

(notice the missing "/" at the end).  This results in

gnu.java.net.protocol.ftp.FTPException: Invalid number of arguments.
   at gnu.java.net.protocol.ftp.FTPConnection.changeWorkingDirectory
(libgcj.so.7)
   at gnu.java.net.protocol.ftp.FTPURLConnection.getInputStream (libgcj.so.7)
   at java.net.URL.openStream (libgcj.so.7)

with gcj (GCC) 4.2.0 20060419 (experimental).

Further, the "while (file.ready())" never seems to return false in Sun's java,
while it does with gcj, so I'd wager on the "obscure bug".


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27163

[Bug classpath/27163] FTP directory listing doesn't work

[tromey at gcc dot gnu dot org]

------- Comment #4 from tromey at gcc dot gnu dot org  2006-04-21 19:05 -------
Ok, I have a fix for the /-less URL bug.

It appears that the JDK somehow waits for some data to be available
on the socket.  I'm not sure exactly what mechanism it uses, however.
It does not appear to buffer all the data; in my tests, a request for
a large file will still only show a few thousand bytes as available().


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27163

[Bug classpath/27163] FTP directory listing doesn't work

[cvs-commit at developer dot classpath dot org]

------- Comment #5 from cvs-commit at developer dot classpath dot org  2006-04-21 21:44 -------
Subject: Bug 27163

CVSROOT:        /cvsroot/classpath
Module name:    classpath
Branch:         
Changes by:     Tom Tromey <tromey@savannah.gnu.org>    06/04/21 21:43:10

Modified files:
        .              : ChangeLog 
        gnu/java/net/protocol/ftp: FTPConnection.java 

Log message:
        PR classpath/27163:
        * gnu/java/net/protocol/ftp/FTPConnection.java
        (changeWorkingDirectory): Do nothing if path is empty.

CVSWeb URLs:
http://cvs.savannah.gnu.org/viewcvs/classpath/classpath/ChangeLog.diff?tr1=1.7184&tr2=1.7185&r1=text&r2=text
http://cvs.savannah.gnu.org/viewcvs/classpath/classpath/gnu/java/net/protocol/ftp/FTPConnection.java.diff?tr1=1.3&tr2=1.4&r1=text&r2=text


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27163

[Bug classpath/27163] FTP directory listing doesn't work

[tromey at gcc dot gnu dot org]

------- Comment #6 from tromey at gcc dot gnu dot org  2006-04-21 21:53 -------
Subject: Bug 27163

Author: tromey
Date: Fri Apr 21 21:53:27 2006
New Revision: 113151

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=113151
Log:
        PR classpath/27163:
        * gnu/java/net/protocol/ftp/FTPConnection.java
        (changeWorkingDirectory): Do nothing if path is empty.

Modified:
    branches/gcc-4_1-branch/libjava/classpath/ChangeLog.gcj
   
branches/gcc-4_1-branch/libjava/classpath/gnu/java/net/protocol/ftp/FTPConnection.java


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27163