I decided to write down the answer for some questions which my book's readers email me or ask me via twitter in my weblog so everyone can benefit from the answers. Here is the answer to the first question which involves custom security realms.
GlassFish supports 5 types of security realms out of the box which are sd follow:
File Realm: Usefull for development and testing purposes. GlassFish...
on May 18, 2010
Do you remember the email you got to tell you that your jre had a vulnerability? No? What about the fact that Java 5 is in an end of life phase. Given the time it has taken for Java 7 to appear its has somewhat slowed the normal EOL pace of the Java platforms. You may not know that Java 1.4.2 for business will be supported commercially until April 2018, which is kind of mind-...
on Apr 28, 2010
Today, a tantalizing announcement by Mark Reinhold about closures in Java 7 has made its way through the twittersphere.
On the same day, Neal Gafter updated his closure proposal (known as the BGGA proposal, named after the initials of Bracha, Gafter, Gosling, and von der Ahé, and not at all related to the B. G. G. A. organization).
Presumably the timing is not a coincidence.
on Nov 18, 2009
Yesterday, a Hudson committer Alan Harder discovered an EOFException in Hudson, which only happens on 64bit JVM on Solaris. This was happening in the part of Hudson (or more precisely, in a separate library called Akuma) where we look at the memory space of the process to figure out the command line arguments of the current process (the /proc/ID/as file — an equivalent of /proc/ID/mem in...
on Sep 17, 2009
Last June, Arnold Schwaighofer push a patch to mlvm repository that
allow to transform tail call invocation
of a method to a jump.
Even if this transformation is classical in language like Lisp, Scheme or Caml,
the JVM was not offering any help to optimize this kind of call until this patch.
Recently, Tom Davies
the patch in order to be used with a more recent...
on Dec 18, 2009
Mark Reinhold recently blogs about the renaissance of
closure in Java (*).
In his blog, he also wrote that in order to have closures in Java,
Java will have to include another feature named
As you may already know, I'm a big fan of closures but
the introduction of extension methods in Java really scary me.
* Ok, they are more lambdas than closures.
on Nov 28, 2009
Java VM embodies
(not in production, in a hacking mode :),
This post shows how to write a non-blocking server with continuations.
Why using continuation with non blocking IO
There are two models when you deals with IO:
the thread model: read and write calls block until they at least read one caracter or write the whole buffer,
so one use thread to be able to...
on Nov 22, 2009
Let me introduce a new language named pseudo (Why this name ?
Why another language ? Why God ? all these questions will be answered
in a later blog).
One great feature of this language is that it allows
i.e. you can assign a type to a parameter, a local variable, etc.
If a variable as no type, the compiler consider it as any.
You can assign any value...
on Nov 1, 2009
Lukas Stadler is my hero, at last JVM summit, he just explain how coroutine and friends can be implemented in the VM and guess what, it now works (currently only with C1).
Let's try to implement something with it.
I have always wanted to have generator in Java. After all, Python have this feature, Ruby and C#(*) too.
A generator is a way to define an iterator but instead of...
on Nov 19, 2009
Entry posted to my new blog.
on Nov 9, 2009
During the JVM Summit, I was doing some tests for
my presentation with the latest
when I've seen some *BIG* performance improvement between jdk7 b71 and jdk7 b72.
A quick look to the summary of changes, hum,
Escape Analysis is now enabled by default.
On my tests, I got a 3x improvement, Wow !
With a quick micro-benchmark, it's even better, as always :)
on Oct 6, 2009