JarURLConnection too slow, why?

Question

Hi,
I'm trying to get some data from a zip file on a local web server. So
i'm using a JarURLConnection object to access to it, however this
objects takes alot to get the file, why?
My code is like this:
import java.net.*;
import java.io.*;
import java.util.*;
import java.util.jar.*;
import java.util.zip.*;
public class Download
     public static void main(String[] args) throws Exception
// Create a URL that refers to a jar file on the net
     // zip file size is 11Mb
URL url = new URL("jar:http://megavit:8080/restaurants.zip!/");
// Get the jar file
JarURLConnection conn = (JarURLConnection)url.openConnection();
     // using a common browser it takes a few seconds to download,
     // however with jrockit it takes several minutes
     // using SUN's jdk it takes a few seconds too...
JarFile jarfile = conn.getJarFile();
Enumeration e = jarfile.entries();
while(e.hasMoreElements())
     ZipEntry ze = (ZipEntry) e.nextElement();
     if(ze.isDirectory())
          System.out.println(ze.getName());
Any help would be appreciated,
Thanks.
Paulo

Answer 1

Cecilia Borg wrote:
Paulo,
Could you describe more about the circumstances around your test? I have set
up the test with a 25MB jar file and cannot see a difference between JRockit
and Hotspot. Which JRockit version do you use and are us specifying any
additional options to the jvm?
Kind regards, Cecilia Borg
BEA WebLogic JRockit
My test is download a local file from localhost's webserver (win32
apache2 on por 8080). I used a network sniffer and i can see the 3-way
handshake from both sockets (java's and apache) and large delay (about 5
minutes) and then the transfer starts and is quite fast.
The problem is that it takes 5 minutes doing nothing... quite weird...
Paulo.