RE: WG: Re-4: [ObjectWeb architecture] just an idea for (Java) n ative comp ilation

["Leskov, Dmitry" <dleskov@xxxxxxxxxxxxxxxxx>]

        Markus,

> > The deployment aspect is ONE important aspect. We also had ENORMOUS 
> > performance improvements compared to JDK 1.3.1 and could NOT use JDK
> 1.4.x 
> > for some JDK incompatibility reasons :-)
> 
> Even if this is off topic: What JDK incompatibility do you mean? We are
> using 1.3 and 1.4 parallel and did not experience such. Can you give me an
> example to prevent us trapping into the same problem?
> 
        From you previous postings I judge that you are developing
complicated apps that run on many different VMs, OS, and hardware, so I am
sure you are aware of many such incompatibilities, but have got so used to
them that you do not consider them as such. Just a few samples:

        public class Hello
        {
            public static void main (String [] args)
            {
                StringBuffer greeting = new StringBuffer ("hello, ");
                StringBuffer who = new StringBuffer (args [0]).append ("!");
                greeting.append (who);
                
                System.out.println (greeting);
            }

        } // End of class

        Compile this with javac from 1.4 and run on 1.3:

        >...\jdk1.3.1\bin\java Hello world
        Exception in thread "main" java.lang.NoSuchMethodError
                at Hello.main(Hello.java:20)

        See http://www.javaworld.com/javaqa/2003-05/02-qa-0523-version.html
for details.

        See
http://www.javaworld.com/javaworld/jw-09-2003/jw-0926-overcome.html for the
discussion of workarounds for JDBC API incompatibilities.

        We have been hit by annoying incompatibilities in AWT/Swing
ourselves. The default font has different size in pixels in 1.3 and 1.4, so
on 1.3 some texts did not fit the respective placeholders. There is a bug in
1.3 in the calculation of the size of the box that the given text would
occupy (if you enable anti-aliasing.) We had to insert some logic to
intercept keypress events on 1.4, because the events are dispatched
differently. Custom L&Fs are just too different, and so on.

        Finally, there is an "official" list of incompatibilities at:

        http://java.sun.com/j2se/1.4/compatibility.html

        With best regards,

        Dmitry Leskov