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Trail: Learning the Java Language: Table of Contents (The Java™ Tutorials)

Trail: Learning the Java Language: Table of Contents (The Java™ Tutorials)
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Track memory allocations Despite the impressive hardware of the first Android phones (T-Mobile G1 and ADP1) writing efficient mobile applications is not always straightforward. Android applications rely on automatic memory management handled by Dalvik's garbage collector which can sometimes cause performance issues if you are not careful with memory allocations. In a performance sensitive code path, like the layout or drawing method of a view or the logic code of a game, any allocation comes at a price. Most of the time, garbage collection occurs because of tons of small, short-lived objects and some garbage collectors, like generational garbage collectors, can optimize the collection of these objects so that the application does not get interrupted too often. To help you avoid frequent garbage collections, the Android SDK ships with a very useful tool called allocation tracker. Once DDMS is running, simply select your application process and then click the Allocation Tracker tab.

Optimisation linéaire Un article de Wikipédia, l'encyclopédie libre. Par exemple, le problème à deux variables suivant qui consiste à minimiser la fonction linéaire sous la contrainte d'inégalité affine et les contraintes de positivité des est un problème d'optimisation linéaire. . Plus généralement, un problème d'OL s'écrira donc en notation matricielle de la manière suivante où est l'inconnue, le vecteur des variables réelles à optimiser, et les données sont des vecteurs et et une matrice . doit être entendue composante par composante : pour tout indice , on doit avoir . est donc bien un polyèdre convexe, puisqu'il s'agit de l'intersection des demi-espaces , pour , en nombre fini. Parmi les problèmes d'optimisation avec contraintes d'inégalité, les problèmes linéaires sont simples à résoudre numériquement. itérations pour une formulation du problème voisine de celle donnée ci-dessus. Beaucoup de problèmes de recherche opérationnelle peuvent être exprimés comme des problèmes d'optimisation linéaire. . . On note si et si .

Plugin Portal Plugin Detail Page [ You have to be logged in to be able to comment. ] Hair Transplant Banglaore hair transplant hyderabad Posted by racheal on Jun 05, 2013 NetBeans OpenGL Pack - plugin detail Awesome blog. Posted by katherine250 on Apr 13, 2013 geertjan on 7.1 How did you succeeded it .It gives The plugin Editor Library is requested in version >= 1.29.2.8.2 error .Under which circumstances we dont need GLSL editor I want to work on OPen-Gl generally not for o specific topic Posted by Malcolmx on Apr 07, 2012 Works fine in 7.1 Hi all, I tried this plugin, or at least a subset of it, in NetBeans IDE 7.1 (on Ubuntu) and have had very positive results: Posted by geertjan on Feb 17, 2012 jogl jogl moved and is still active Posted by mbien on Sep 12, 2011 too sad that this project is dead. and what about jogl?? Posted by habernir on Sep 12, 2011 status Posted by mbien on Sep 03, 2011 this project is dead?? anyone know what happen to this project??? thanks Hi, mac?

On Memory Leaks in Java and in Android. | Development Chaos Theory Just because it’s a garbage collected language doesn’t mean you can’t leak memory or run out of it. Especially on Android where you get so little to begin with. Now of course sometimes the answer is that you just need more memory. If your program is a Java command line program to load the entire road map of the United States to do some network algorithms, you probably need more than the default JVM configurations give you. Sometimes it’s not even a full-on leak, but a large chunk of memory isn’t being released in time as a consequence of some holder object that isn’t being released in time. There are some tools that can help. public void onCreate(Bundle savedInstanceState) { ... One place where I’ve been running into issues is with a clever little bit of code which loads images from a separate thread from a remote resource, and puts them into a custom view that replaces the ImageView class. Can you spot the leak? I didn’t, at first. Here’s a hint: Avoiding Memory Leaks No? Okay, here goes.

Apprenez à programmer en Java Bonjour à tous ! :D Bienvenue dans mon cours de programmation en Java. Voici les caractéristiques de Java en quelques mots : Java est un langage de programmation moderne développé par Sun Microsystems (aujourd'hui racheté par Oracle). On peut faire de nombreuses sortes de programmes avec Java : des applications, sous forme de fenêtre ou de console ;des applets, qui sont des programmes Java incorporés à des pages web ; des applications pour appareils mobiles, avec J2ME ;et bien d'autres ! Comme vous le voyez, Java permet de réaliser une très grande quantité d'applications différentes ! Heureusement, ce cours est là pour tout vous apprendre de Java à partir de zéro :) . Scrum (development) Scrum is an iterative and incremental agile software development framework for managing product development. It defines "a flexible, holistic product development strategy where a development team works as a unit to reach a common goal", challenges assumptions of the "traditional, sequential approach" to product development, and enables teams to self-organize by encouraging physical co-location or close online collaboration of all team members, as well as daily face-to-face communication among all team members and disciplines in the project. A key principle of Scrum is its recognition that during a project the customers can change their minds about what they want and need (often called "requirements churn"), and that unpredicted challenges cannot be easily addressed in a traditional predictive or planned manner. Later, Schwaber with others founded the Scrum Alliance and created the Certified Scrum Master programs and its derivatives. Each sprint is started by a planning meeting.

Get Involved Android is an open-source software stack created for a wide array of devices with different form factors. The primary purposes of Android are to create an open software platform available for carriers, OEMs, and developers to make their innovative ideas a reality and to introduce a successful, real-world product that improves the mobile experience for users. We also wanted to make sure there was no central point of failure, where one industry player could restrict or control the innovations of any other. Android was originated by a group of companies known as the Open Handset Alliance, led by Google. The companies that have invested in Android have done so on its merits because we believe an open platform is necessary. Uncontrolled customization can, of course, lead to incompatible implementations. The Android Open Source Project is led by Google, who maintains and further develops Android.

H ritage Multiple Plusieurs langages à objets, par exemple C++ et Eiffel, offrent le concept d'héritage multiple. Dans ces langages, une sous-classe peut hériter de deux ou de plusieurs super-classes immédiates. Ceci pose un certain nombre de problèmes non triviaux, aussi bien au niveau de la définition du langage qu'à celui de son implémentation. Le graphe d'héritage d'une application donnée n'a, en général, plus la forme d'un arbre, ou d'une forêt dont les arbres individuels sont issus de classes racines disjointes, mais d'un DAG. On suppose, en-effet, qu'il n'est pas possible de définir une relation d'héritage circulaire dans laquelle une classe pourrait hériter (directement ou indirectement) d'elle-même. Il est par contre possible qu'une classe hérite d'une même super-classe par deux, ou plusieurs, chemins distincts. Ceci pose un premier problème au niveau de la définition du langage. Il n'est pas possible de définir des règles de visibilité qui satisfassent ces contraintes dans tous les cas. Exemple:

parameter passing - Is Java "pass-by-reference" FAQ C++ Cette FAQ a été réalisée à partir des questions fréquemment posées sur les forums de et de l'expérience personnelle des auteurs. Je tiens à souligner que cette FAQ ne garantit en aucun cas que les informations qu'elle propose sont correctes ; les auteurs font le maximum, mais l'erreur est humaine. Cette FAQ ne prétend pas non plus être complète. Si vous trouvez une erreur ou si vous souhaitez devenir rédacteur, lisez ceci. Sur ce, nous vous souhaitons une bonne lecture. Les sources présentées sur cette page sont libres de droits et vous pouvez les utiliser à votre convenance.

10 Things You Didn't Know About Java So, you’ve been working with Java since the very beginning? Remember the days when it was called “Oak”, when OO was still a hot topic, when C++ folks thought that Java had no chance, when Applets were still a thing? I bet that you didn’t know at least half of the following things. Let’s start this week with some great surprises about the inner workings of Java. 1. That’s right! Today, everyone agrees that checked exceptions were a mistake. Do you want proof that the JVM doesn’t know such a thing? 01.public class Test { 04. public static void main(String[] args) { 05. doThrow(new SQLException()); 08. static void doThrow(Exception e) { 09. 12. 13. static <E extends Exception> 14. void doThrow0(Exception e) throws E { 15. throw (E) e; Not only does this compile, this also actually throws the SQLException, you don’t even need Lombok’s @SneakyThrows for that. More details about the above can be found in this article here, or here, on Stack Overflow. 2. That doesn’t compile, right? 1.class Test { 2. 3.

Just-in-time compilation Applications[edit] A common implementation of JIT compilation is to first have AOT compilation to bytecode (virtual machine code), known as bytecode compilation, and then have JIT compilation to machine code (dynamic compilation), rather than interpretation of the bytecode. This improves the runtime performance compared to interpretation, at the cost of lag due to compilation. JIT compilers translate continuously, as with interpreters, but caching of compiled code minimizes lag on future execution of the same code during a given run. Since only part of the program is compiled, there is significantly less lag than if the entire program were compiled prior to execution. Overview[edit] In a bytecode-compiled system, source code is translated to an intermediate representation known as bytecode. In contrast, a traditional interpreted virtual machine will simply interpret the bytecode, generally with much lower performance. JIT code generally offers far better performance than interpreters.

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