Hello,

I'm trying to extend a web-chat applet by adding gzip-compression.

The data sent from the web-server is really ok: I'm looking at it
using tcpdump (full output listed at the bottom) and see that the
content-length (32) matches the length of the body and that the
compressed bytes match the string I'm sending by my Apache
module ("player=Vasja").

However I can't read the data in my applet - I get an EOFException:

Mon Mar 20 18:13:07 CET 2006 dis=java.io.DataInputStream@6f9b8e
Mon Mar 20 18:13:07 CET 2006 getData, status=HTTP/1.1 200 OK
Mon Mar 20 18:13:07 CET 2006 getData, clength=32
Mon Mar 20 18:13:07 CET 2006 getData,
dis=java.io.DataInputStream@6f9b8e
java.io.EOFException
       at java.io.DataInputStream.readFully(DataInputStream.java:178)
       at java.io.DataInputStream.readFully(DataInputStream.java:152)
       at Net.getData(Net.java:133)
       at Pref.run(Pref.java:165)
       at java.lang.Thread.run(Thread.java:595)
Mon Mar 20 18:13:07 CET 2006 getData end

Here is my code. Does anybody please know what is wrong there?
Aren't I allowed to contstruct DataInputStream(new GZIPInputStream(
URLConnection.getInputStream())) and call readFully on it?

       try {
               DataInputStream dis;

               URLConnection conn = url.openConnection();
               if (modified != 0)
                       conn.setIfModifiedSince(modified);
               conn.setRequestProperty("Accept-Encoding", "gzip");

               int clength = conn.getContentLength();
               String encoding = conn.getContentEncoding();
               if (encoding != null &&
                   encoding.equalsIgnoreCase("gzip")) {
                       dis = new DataInputStream(new
                           GZIPInputStream(conn.getInputStream()));
                       trace("dis=" + dis);
               } else
                       dis =
                         new DataInputStream(conn.getInputStream());

               trace("getData, status=" + conn.getHeaderField(0));
               trace("getData, clength=" + clength);
               trace("getData, dis=" + dis);

               if (clength > 0) {
                       byte[] body = new byte[clength];
                       dis.readFully(body);     // line 133
                       trace("getData, body=" + new String(body));

                       modified = conn.getLastModified();
                       hol = parseResponse(new String(body));
               }

               dis.close();
               url = null;
       } catch (Exception ex) {
               ex.printStackTrace();
       }

When I disable gzip both in the applet and my server ( preferans.de ),
then everything works as I want, even the HTTP Keep-Alive.

Thank you
Alex

------
16:31:50.804896 127.0.0.1.80 > 127.0.0.1.35892: P 33174:33526(352) ack
36097 win 16384 <nop,nop,timestamp 146348926 0> (DF)
 0000: 4500 0194 4f04 4000 4006 ec5d 7f00 0001  E...O.@.@.ì]....
 0010: 7f00 0001 0050 8c34 3750 0ec8 7452 e306  .....P.47P.ÈtRã.
 0020: 8018 4000 fe8d 0000 0101 080a 08b9 1b7e  ..@.þ........¹.~
 0030: 0000 0000 4854 5450 2f31 2e31 2032 3030  ....HTTP/1.1 200
 0040: 204f 4b0d 0a44 6174 653a 204d 6f6e 2c20   OK..Date: Mon,
 0050: 3230 204d 6172 2032 3030 3620 3136 3a33  20 Mar 2006 16:3
 0060: 313a 3530 2047 4d54 0d0a 5365 7276 6572  1:50 GMT..Server
 0070: 3a20 4170 6163 6865 2f31 2e33 2e32 3920  : Apache/1.3.29
 0080: 2855 6e69 7829 2050 4850 2f35 2e30 2e35  (Unix) PHP/5.0.5
 0090: 206d 6f64 5f73 736c 2f32 2e38 2e31 3620   mod_ssl/2.8.16
 00a0: 4f70 656e 5353 4c2f 302e 392e 3767 0d0a  OpenSSL/0.9.7g..
 00b0: 4c61 7374 2d4d 6f64 6966 6965 643a 204d  Last-Modified: M
 00c0: 6f6e 2c20 3230 204d 6172 2032 3030 3620  on, 20 Mar 2006
 00d0: 3136 3a33 313a 3439 2047 4d54 0d0a 436f  16:31:49 GMT..Co
 00e0: 6e74 656e 742d 4c65 6e67 7468 3a20 3332  ntent-Length: 32
 00f0: 0d0a 436f 6e74 656e 742d 456e 636f 6469  ..Content-Encodi
 0100: 6e67 3a20 677a 6970 0d0a 4b65 6570 2d41  ng: gzip..Keep-A
 0110: 6c69 7665 3a20 7469 6d65 6f75 743d 3930  live: timeout=90
 0120: 2c20 6d61 783d 310d 0a43 6f6e 6e65 6374  , max=1..Connect
 0130: 696f 6e3a 204b 6565 702d 416c 6976 650d  ion: Keep-Alive.
 0140: 0a43 6f6e 7465 6e74 2d54 7970 653a 2061  .Content-Type: a
 0150: 7070 6c69 6361 7469 6f6e 2f78 2d77 7777  pplication/x-www
 0160: 2d66 6f72 6d2d 7572 6c65 6e63 6f64 6564  -form-urlencoded
 0170: 0d0a 0d0a 1f8b 0800 0000 0000 0003 2bc8  ..............+È
 0180: 49ac 4c2d b20d 4b2c ce4a 0400 ed8c b5fb  I¬L-².K,ÎJ..í.µû
 0190: 0c00 0000                                ....

(as you see there are even 2 magic gzip bytes above: 1f and 8b).

laptop:afarber {533} echo -n "player=Vasja" | gzip -c | xxd
0000000: 1f8b 0800 0000 0000 0003 2bc8 49ac 4c2d  ..........+.I.L-
0000010: b20d 4b2c ce4a 0400 ed8c b5fb 0c00 0000  ..K,.J..........