vendredi 1 juillet 2011

Veille technologique semaine 26

Pour le bulletin de cette semaine, je vous propose les sujets suivants :
  • le prochain standard C++ devrait être prêt avant la fin de l'année. Le précédant date de 1998.
  • Oracle confirme que OpenJDK est l'implémentation de référence qui sert de base à la distribution d'Oracle.
  • Changement du look de la Javadoc du JDK7 : changement des stylesheet.
  • Un résumé de la présentation du framework Akka : le pattern actor pour des systèmes distribués, scallable et tolérant au panne.
  • Un chapitre : la meilleur ligne de code est celle qui n'est pas nécessaire. Pourquoi réduire le nombre de lignes de code.
  • Présentation d'un runtime pour faire exécuter les applications android (présent sur les smart phones et tablettes avec le processeur ARM) en natif processeur x86 sur windows.
  • Le pattern object null en remplacement des exceptions NullPointerException : l'invention qui a coûté très chère.
  • La gestion des ressources dans la syntaxe du JDK 7
  • Les classes atomiques du JDK 5 : comment faire des lecture-modification-ecriture sans verrous.
  • La classe Objects du JDK 7 et la méthode equals().

Bonne lecture

The New C++: Lay down your guns, knives, and clubs
"The world is built on C++," Herb Sutter tells The Reg. Considering he's one of the language's chief stewards, we question his impartiality. But he does have a point. After more than 30 years – depending on whose numbers you swallow (these or these) – C++ remains one of computing's most popular programming languages, favored for its speed if not its simplicity.
Apple's Mac OS X, Adobe Illustrator, Facebook, Google's Chrome browser, the Apache MapReduce clustered data-processing architecture, Microsoft Windows 7 and Internet Explorer, Firefox, and MySQL – to name just a handful – are written in part or in their entirety with C++.

And while new languages have since been born, C++ has endured. Java is the only one to have outpaced it in popularity, according to the TIOBE Index. PHP, Ruby, and JavaScript? Sure, some might claim that they are the future, but C++ is the past, the present, and the future.

According to Sutter, C++ is on the verge of its biggest change in the 13 years since it became an official ISO standard, a change that will make it relevant for the next two decades.
The recently finished C++ ISO standard, with the working name of C++0x, is due to be published this summer, following the finishing touches to the ISO spec language and standards wonks agreed upon in March.

Sutter didn't create C++, but he is chair of the ISO's C++ committee in addition to being a noted C++ programmer, author, and chief native-languages architect at Microsoft.

OpenJDK to be Java SE 7 Reference Implementation, Bylaws Ratified by Oracle
The OpenJDK Community Bylaws have been ratified, with 70 votes in favour, no votes against, and nine abstentions. Whilst this represents a major milestone for the OpenJDK project, building from an effort which was started by Sun in 2007, it should be noted that 61 of the yes votes were from Oracle employees, and 46 people who were eligible to vote didn't bother.

New Java SE 7 Javadoc API Documentation Appearance
In my last post, I briefly referenced the Jonathan Gibbons's post What's Up, JavaDoc? that describes some recent changes to Javadoc, including changes that allow a CSS stylesheet to be applied to the documentation. Mark Reinhold's post JDK 7: Are we there yet? talks about the changes to the Java SE 7 API default display style. In this post, I briefly look at this change.

Akka: Simpler Scalability, Fault-Tolerance, Concurrency & Remoting through Actors"
Lors de la What's Next, Jonas Bonér a présenté Akka, un framework facilitant la réalisation d'applications concurrentes, pouvant passer à l'échelle et tolérantes aux erreurs. Cet article tente de retranscrire le contenu de cette présentation.

Chapter 14. Writing Less Code
Knowing when not to code is possibly the most important skill a programmer can learn. By reusing libraries or eliminating features, you can keep your code base lean and mean. Every line of code you write is a line that has to be maintained.

The most readable code is no code at all.

The best way to cope is to keep your code base as small and lightweight as possible, even as your project grows.

Native x86 Android runtime will enable Android apps on Windows
A startup called BlueStacks has developed an Android runtime environment for the Windows operating system. It will enable users to run Android applications alongside conventional Windows software on Microsoft's operating system.
The technology impressed some major investors who have supplied $7.6 million in Series A funding so that BlueStacks can turn its software into a business.

Presentation: "Null References: The Billion Dollar Mistake"
Abstract: I call it my billion-dollar mistake. It was the invention of the null reference in 1965. At that time, I was designing the first comprehensive type system for references in an object oriented language (ALGOL W). My goal was to ensure that all use of references should be absolutely safe, with checking performed automatically by the compiler. But I couldn't resist the temptation to put in a null reference, simply because it was so easy to implement. This has led to innumerable errors, vulnerabilities, and system crashes, which have probably caused a billion dollars of pain and damage in the last forty years. In recent years, a number of program analysers like PREfix and PREfast in Microsoft have been used to check references, and give warnings if there is a risk they may be non-null. More recent programming languages like Spec# have introduced declarations for non-null references. This is the solution, which I rejected in 1965.

Better Resource Management with Java SE 7: Beyond Syntactic Sugar
The typical Java application manipulates several types of resources such as files, streams, sockets, and database connections. Such resources must be handled with great care, because they acquire system resources for their operations. Thus, you need to ensure that they get freed even in case of errors. Indeed, incorrect resource management is a common source of failures in production applications, with the usual pitfalls being database connections and file descriptors remaining opened after an exception has occurred somewhere else in the code. This leads to application servers being frequently restarted when resource exhaustion occurs, because operating systems and server applications generally have an upper-bound limit
for resources.

Java theory and practice: Going atomic
Summary: Until JDK 5.0, it was not possible to write wait-free, lock-free algorithms in the Java language without using native code. The addition of the atomic variable classes in java.util.concurrent changes that situation. Follow along with concurrency expert Brian Goetz as he explains how these new classes have enabled the development of highly scalable nonblocking algorithms in the Java language.

Java 7 Objects-Powered Compact Equals
Obi Ezechukwu's blog High-Octane Java recently featured the post Compact Equals, which compares an implementation of a Java class's overridden equals method in traditional form versus one implemented using arrays of the class's fields and then invoking Arrays.equals on those arrays. I am using this blog post to build upon these examples to demonstrate the utility of Java 7's Objects.equals(Object, Object) method and will demonstrate the usefulness of Objects.hash(Object...) along the way.

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