Search Results

Search found 45920 results on 1837 pages for 'java design patterns'.

Page 63/1837 | < Previous Page | 59 60 61 62 63 64 65 66 67 68 69 70  | Next Page >

• Java EE 7 turns one today!

  - by delabassee

  "Tell me and I forget. Teach me and I remember. Involve me and I learn." (Benjamin Franklin) Today marks the first year anniversary of Java EE 7. The JSR 342 specification was finalised on May 28, 2013 with the official launch taking place on June 12, 2013 (original press release). As of today, there are already 3 Java EE 7 compatible Application Servers, coming from different 'vendors' (Oracle, TmaxSoft and Red Hat). Two of those Java EE 7 Application Servers are free and open source. We expect the list of Java EE 7 compatible Application Servers to grow over the coming months. Source: RebelLabs - 'Java Tools and Technologies Landscape for 2014' According to a recent independent survey, one third of the Java EE users who participated in that survey is already using Java EE 7. This is a good sign but it also means that a lot of people are not yet on Java EE 7. So if you haven't yet embarked on Java EE 7, now is really the time to do so! There are various ways to learn Java EE 7, in no particular order ... Continue to read The Aquarium. Through this blog, we are relaying Java EE news but we are also doing our best to highlight relevant technical contents such as articles, community tutorials, etc. Watch the GlassFish YouTube channel. Amongst others, it contains the different videos of the Java EE 7 launch, those videos will give you good technical update on Java EE and its different components specifications (JMS 2.0, JAX-RS 2.0, EJB 3.2, etc.) Take a formal training. Oracle University is starting to roll-out Java EE 7 trainings like the 'Java EE 7: New Features' class.  Attend conferences and JUGs sessions. On that note, we have spent a lot of time to create a strong JavaOne 'Server-Side Java' track. It's still possible to benefit from the early bird JavaOne pricing but don't wait too much! Read books. There are more than 25 (!) books related to Java EE 7 or to one of the Java EE 7 component specification.  There are many more ways to learn Java EE but if I have to suggest one and only one way, I would recommend the Java EE 7 Tutorial. It's exhaustive and clear, it's free and it continues to evolve. And finally as the introductory quote suggest, participation is key to learning. Participate in JUGs,  participate in Adopt-a-JSR, get involved in the different open source communities evolving around Java EE, participate in the JCP... in one word, participate!

  Read the article

• rts libgdx design?

  - by user36531

  I am attempting to create a simple rts multi-player strategy game using libgdx. I am stumped at the moment. I want the underlying game world to run at all times and be aware of where all items are on the map.. so if player A logs in and moves unit to some location on the grid and logs off, that unit info is still there and can be accessed again by player A when they log back on to move somewhere else (if it didnt get attacked during the playerA was logged off). How can i do this? Do i create a main game world on the server and when players connect make client just sequentially request whats in each visible tile? Is there an easier way to get this done? Or go SQL route? Whats better?

  Read the article

• Class design, One class in two sources

  - by Pavla

  Is it possible define methods from the same class in different "CPP" files? I have header file "myClass.h" with: class myClass { public: // methods for counting ... // methods for other ... }; I would like to define "methods for counting" in one CPP and "methods for other" in other CPP. For clarity. Both groups of methods sometime use the same attributes. Is it possible? Thanks :).

  Read the article

• Is throwing an error in unpredictable subclass-specific circumstances a violation of LSP?

  - by Motti Strom

  Say, I wanted to create a Java List<String> (see spec) implementation that uses a complex subsystem, such as a database or file system, for its store so that it becomes a simple persistent collection rather than an basic in-memory one. (We're limiting it specifically to a List of Strings for the purposes of discussion, but it could extended to automatically de-/serialise any object, with some help. We can also provide persistent Sets, Maps and so on in this way too.) So here's a skeleton implementation: class DbBackedList implements List<String> { private DbBackedList() {} /** Returns a list, possibly non-empty */ public static getList() { return new DbBackedList(); } public String get(int index) { return Db.getTable().getRow(i).asString(); // may throw DbExceptions! } // add(String), add(int, String), etc. ... } My problem lies with the fact that the underlying DB API may encounter connection errors that are not specified in the List interface that it should throw. My problem is whether this violates Liskov's Substitution Principle (LSP). Bob Martin actually gives an example of a PersistentSet in his paper on LSP that violates LSP. The difference is that his newly-specified Exception there is determined by the inserted value and so is strengthening the precondition. In my case the connection/read error is unpredictable and due to external factors and so is not technically a new precondition, merely an error of circumstance, perhaps like OutOfMemoryError which can occur even when unspecified. In normal circumstances, the new Error/Exception might never be thrown. (The caller could catch if it is aware of the possibility, just as a memory-restricted Java program might specifically catch OOME.) Is this therefore a valid argument for throwing an extra error and can I still claim to be a valid java.util.List (or pick your SDK/language/collection in general) and not in violation of LSP? If this does indeed violate LSP and thus not practically usable, I have provided two less-palatable alternative solutions as answers that you can comment on, see below. Footnote: Use Cases In the simplest case, the goal is to provide a familiar interface for cases when (say) a database is just being used as a persistent list, and allow regular List operations such as search, subList and iteration. Another, more adventurous, use-case is as a slot-in replacement for libraries that work with basic Lists, e.g if we have a third-party task queue that usually works with a plain List: new TaskWorkQueue(new ArrayList<String>()).start() which is susceptible to losing all it's queue in event of a crash, if we just replace this with: new TaskWorkQueue(new DbBackedList()).start() we get a instant persistence and the ability to share the tasks amongst more than one machine. In either case, we could either handle connection/read exceptions that are thrown, perhaps retrying the connection/read first, or allow them to throw and crash the program (e.g. if we can't change the TaskWorkQueue code).

  Read the article

• Game World Design [on hold]

  - by GameDev

  I have one doubt about world game developing. I want to do a kind of platform game mixed with RPG (Side Scroll). What's the best to draw the world, - Draw everything than use the camera to move around the world - Draw just what you see as the player moves draw the new stuff. I'm new at this and didn't had any course for it. So if anyone can help me thanks :) PS: Any recommendation to learning game concept, like drawing world theory, play etc.. (not code and i want to 2D and i only see books for 3D stuff)

  Read the article

• Design of input files reading when it comes to defaults/transformations

  - by Stefano Borini

  Suppose you have an application that reads an input file, on a language that does not support the concept of None. The input is read, parsed, and the contents are stored on a structure for later use. Now, in general you want to keep into account transformation of the data from the input, such as adding default values when not specified, or adding full path information to relative path specified in the input. There are two different strategies to achieve this. The first strategy is to perform these transformations at input file reading time. In practice, you put all the intelligence into the input parser, and your application has no logic to deal with unexpected circumstances, such as an unspecified value. You lose the information of what was specified and what wasn't, but you gain in black-boxing the details. Your "running code" needs that information in any case and in a proper form, and is not concerned if it's the default or a user-specified information. The second strategy is to have the file reader a real one-to-one mapper from the file to a memory-stored object, with no intelligent behavior. unspecified values are not filled (which may however be a problem in languages not supporting None) and data is stored verbatim from the file. The intelligence for recovery must now go into the "running code", which must check what was specified in the file, eventually fall back to a default, or modify the input properly before using it. I would like to know your opinion on these two approaches, and in particular which one you found the most frequently implemented.

  Read the article

• Replicate GAE Datastore On A Server LAN in Java

  - by Franz Noel

  There may be instances wherein one Company Client may not have internet connection on their vicinity. Either their Internet Service Provider currently experience a down time or there are some other problems involving the network, but not their LAN. GAE seems to be needing a connection at all times in the internet. I only need GAE Datastore. I'm thinking about a different application. Creating a Java Swing Client, for instance, and connecting to the Office Server via HRD of GAE Datastore. When I tried to check on the solutions for Java, it does not say anything about uploading all data and I do not need the App. I just need the GAE Datastore. In Java GAE, only indexes can be able to be manipulated. So, is there any tricks/ideas that you can use HRD with GAE Datastore on Java with an Internal Office Server combined? This way, it may provide service even during network down times. (Can somebody create me a tag of gae-datastore, please.)

  Read the article

• MMORPG design for time-limited players

  - by Philipp

  I believe that there is a significant market of players who would enjoy the exploration and interaction aspects of MMORPGs, but simply don't have the time for the endless grinding marathons which are part of the average MMORPG. MMORPGs are all about interaction between players. But when different players have different amounts of time to invest into a game, those with less time to spend will soon lack behind their power-leveling friends and won't be able to interact with them anymore. One way to solve this would be to limit the progress a player can achieve per day, so that it simply doesn't make sense to play more than one or two hours a day. But even the busiest casual players sometimes like to spend a whole sunday afternoon playing a video game. Just stopping them after two hours would be really frustrating. It also creates a pressure to use the daily progress limit every day, because otherwise the player would feel like wasting something. This pressure would be detrimental for casual gamers. What else could be done to level the playing field between those players who play 40+ hours a week and those who can't play more than 10?

  Read the article

• Java SE 6 Update 23 is released!

  - by [email protected]

  Java SE 6 Update 23 includes the following key changes: Java VisualVM 1.3.1 introduces the following features and enhancements:           o Added Java version and vendor information to the application Overview view           o Built on NetBeans Platform and profiler 6.9.1 Swing JMenuItem Corrections for right-to-left languages           o Non-default alignment and text orientation for the menu items in Swing have been fixed           o The position of the icon and the text where text used to overlap the icon in a menu item was corrected           o All platform Look and Feel configurations will now handle menu items in right-to-left language situations. Updated HotSpot 19 JVM Engine with improvements to overall performance and reliability. Additional Languages support in SuSE Linux Enterprise Server 10 and 11 on Chinese(Simplified), Chinese (Traditional), Japanese, and Korean locales. Supported system configuration, check - http://java.sun.com/javase/6/webnotes/install/system-configurations.htmlSee Release Notes for additional details.

  Read the article

• API Design Techniques

  - by Dehumanizer

  Is it right or more beautiful to name the functions with an prefix, like in Qt? Or using "many" namespaces, but 'normal' names for functions? For example, slOpenFile(); //"sl" means "some lib" vs some_lib::file_functions::openFile(); UPD: I've read somewhere that the first variant(using some prefix) is better, because the API users can perform 'fast' search among the documentation and in the Internet. E.g. by typing the magic prefix search engine starts to advice the exact functions. Is it enough to use the first variant?

  Read the article

• Design: classes with same implementation but different method names

  - by Dror Helper

  I have multiple classes that have similar implementation for different named methods: class MyClassX { public int MyClassXIntMethod(){} public string MyClassXStringMethod(){} } class MyClassY { public int MyClassYIntMethod(){} public string MyClassYStringMethod(){} } the methods inside the classes have similar implementation but because the method's names are different (due to 3rd party constraints) i cannot use inheritance. I'm looking for an elegant solution that would be better than implementing the same functionality over and over again.

  Read the article

• Software design for non object oriented paradigm

  - by Dean

  I'm currently working on a project where I'm writing the firmware for an electronic system in C, and have been asked to produce documentation on the development/evolution of the software for the embedded devices. Having developed software in the object oriented paradigm I know to use UML to document the software such as class diagrams with objects, however this does not work for documenting the development of my embedded system. So what should I produce to document the development of my firmware?

  Read the article

• Java applet game design no keyboard focus

  - by Sri Harsha Chilakapati

  THIS IS PROBABLY THE WRONG PLACE. POSTED ITHERE (STACKOVERFLOW) I'm making an applet game and it is rendering, the game loop is running, the animations are updating, but the keyboard input is not working. Here's an SSCCE. public class Game extends JApplet implements Runnable { public void init(){ // Initialize the game when called by browser setFocusable(true); requestFocus(); requestFocusInWindow(); // Always returning false GInput.install(this); // Install the input manager for this class new Thread(this).start(); } public void run(){ startGameLoop(); } } And Here's the GInput class. public class GInput implements KeyListener { public static void install(Component c){ new GInput(c); } public GInput(Component c){ c.addKeyListener(this); } public void keyPressed(KeyEvent e){ System.out.println("A key has been pressed"); } ...... } This is my GInput class. When run as an applet, it doesn't work and when I add the Game class to a frame, it works properly. Thanks

  Read the article

• API design and versioning using EJB

  - by broschb

  I have an API that is EJB based (i.e. there are remote interfaces defined) that most of the clients use. As the client base grows there are issues with updates to the API and forcing clients to have to update to the latest version and interface definition. I would like to possibly look at having a couple versions of the API deployed at a time (i.e. have multiple EAR files deployed with different versions of the API) to support not forcing the clients to update as frequently. I am not concerned about the actual deployment of this, but instead am looking for thoughts and experiences that others have on using EJB's as an API client. How do you support updating versions, are clients required to update? Does anyone run multiple versions in a production environment? Are there pro's cons? Any other experiences or thoughts on this approach, and having an EJB centric API?

  Read the article

• How to deal with Character body parts from Design to Cocos2d

  - by Edwin Soho

  I'm trying to figure out the pattern the game developers use together with game designers: See the picture below with the independent parts: Questions: 1) Should I create different image parts from different body parts or keep frame by frame animaton? (I know both can be used, but I'm trying to figure what is commonly used in the industry) 2) If I'm going to generate different image parts from different body parts (which is I thing is more logical) how would I export that to Cocos2d (Vector or Bitmap)?

  Read the article

• Facebook Game database design

  - by facebook-100000781341887

  Hi, I'm currently develop a facebook mafia like PHP game(of course, a light weight version), here is a simplify database(MySQL) of the game id-a <int3> <for index> uid <chr15> <facebook uid> HP <int3> <health point> exp <int3> <experience> money <int3> <money> list_inventory <chr5> <the inventory user hold...some special here, talk next> ... and 20 other fields just like reputation, num of combat... *the number next to the type is the size(byte) of the type For the list_inventory, there have 40 inventorys in my game, (actually, I have 5 these kind of list in my database), and each user can only contain 1 qty of each inventory, therefore, I assign 5 char for this field and each bit of char as 1 item(5 char * 8 bit = 40 slot), and I will do some manipulation by PHP to extract the data from this 5 byte. OK, I was thinking on this, if this game contains 100,000 user, and only 10% are active, therefore, if use my method, for the space use, 5 byte * 100,000 = 500 KB if I use another method, create a table user_hold_inventory, if the user have the inventory, then insert a record into this table, so, for 10,000 active user, I assume they got all item, but for other, I assume they got no item, here is the fields of the new table id-b <int3> <for index> id-a <int3> <id of the user table> inv_no <int1> <inventory that user hold> for the space use, ([id] (3+3) byte + [inv_no] 1 byte ) * [active user] 10,000 * [all inventory] * 40 = 2.8 MB seems method 2 have use more space, but it consume less CPU power. Please comment these 2 method or please correct me if there have another better method rather than what I think. Another question is, my database contain 26 fields, but I counted 5 of them are not change frquently, should I need to separate it on the other table or not? So many words, thanks for reading :)

  Read the article

• Optimal Database design regarding functionality of letting user share posts by other users

  - by codecool

  I want to implement functionality which let user share posts by other users similar to what Facebook and Google+ share button and twitter retweet. There are 2 choices: 1) I create duplicate copy of the post and have a column which keeps track of the original post id and makes clear this is a shared post. 2) I have a separate table shared post where I save the post id which is a foreign key to post id in post table. Talking in terms of programming basically I keep pointer to the original post in a separate table and when need to get post posted by user and also shared ones I do a left join on post and shared post table Post(post_id(PK), post_content, posted_by) SharedPost(post_id(FK to Post.post_id), sharing_user, sharedfrom(in case someone shares from non owners profile)) I am in favour of second choice but wanted to know the advice of experts out there? One thing more posts on my webapp will be more on the lines of facebook size not tweet size.

  Read the article

• Should we consider code language upon design?

  - by Codex73

  Summary This question aims to conclude if an applications usage will be a consideration when deciding upon development language. What factors if any could be considered upon language writing could be taken into context. Application Type: Web Question Of the following popular languages, when should we use one or the other? What factors if any could be considered upon language writing could be taken into context. Languages PHP Ruby Python My initial thought is that language shouldn't be considered as much as framework. Things to consider on framework are scalability, usage, load, portability, modularity and many more. Things to consider on Code Writing maybe cost, framework stability, community, etc.

  Read the article

• Java's Object.wait method with nanoseconds: Is this a joke or am I missing something

  - by Krumia

  I was checking out the Java API source code (Java 8) just out of curiosity. And I found this in java/lang/Object.java. There are three methods named wait: public final native void wait(long timeout): This is the core of all wait methods, which has a native implementation. public final void wait(): Just calls wait(0). And then there is public final void wait(long timeout, int nanos). The JavaDoc for the particular method tells me that, This method is similar to the wait method of one argument, but it allows finer control over the amount of time to wait for a notification before giving up. The amount of real time, measured in nanoseconds, is given by: 1000000*timeout+nanos But this is how the methods achieves "finer control over the amount of time to wait": if (nanos >= 500000 || (nanos != 0 && timeout == 0)) { timeout++; } wait(timeout); So this method basically does a crude rounding up of nanoseconds to milliseconds. Not to mention that anything below 500000ns/0.5ms will be ignored. Is this piece of code bad/unnecessary code, or am I missing some unseen virtue of declaring this method, and it's no argument cousin as the way they are?

  Read the article

• PyQt design issues

  - by Falmarri

  I've been working on a my first real project using PyQt lately. I've done just a little bit of work in Qt for C++ but nothing more than just messing around. I've found that the Qt python bindings are essentially just a straight port of C++ classes into python, which makes sense. The issue is that this creates a lot of messy, unpythonic code. For example if you look at QAbstractItemModel, there's a lot of hoops you have to go through that forces you to hide the actual python. I was just wondering if there's any intention of writing a python implementation of Qt that isn't necessarily just a wrapper? Either by Nokia or anyone else? I really like Qt but I would love to be able to write more pythonic code. I hope this is OK to ask here. I'm not trying to start a GUI war or anything.

  Read the article

• Inventory management system design problem

  - by Steve F

  What are the conventions for item batch identifiers in inventory management systems? For example: A retail supermarket can order 'Item X' from either 'Supplier A' or 'Supplier B'. When it completes an order for the item from either supplier, it needs to store the record of the receipt. Inventory quantity for the item is increased upon receipt of the order. However it is also required to store some record of the supplier. Thus some sort of batch identifier is required. This batch identifier will uniquely identify the item received and the supplier from whom it is received. A new batch is created each time items are received in stock (for example, after an order). Hence, for purposes of accounting / auditing, information available to identify an item after it was sold comprises of ITEM_CODE, ITEM_NAME, BATCH_CODE. The BATCH_CODE is unique and is associated with DATE_RECEIVED, SUPPLIER_CODE, QTY_RECEIVED. Is this a complete system specification for the above scenario or has anything significant been left out?

  Read the article

• How Would You Design This Table?

  - by sooprise

  I have to create a table where each row needs to store 50 number values. Each row will always need to store 50 number values. If this was a smaller number of values, I would just make fields for each of the values, but because there are 50, this approach seems a bit cumbersome (but since it will always be 50 values, maybe this is the correct approach?). Is there a way to store an array of values in a field? This seems like a nice solution, but the concept is almost identical to creating a relational database.

  Read the article

• How to design brain games [on hold]

  - by samesky

  I will wonder if anybody has some information about designing games for brain improvement. Recently lumosity is into a gear. I guess they research a lot or have experts. But is there any other research paper that is publicly available for designing the brain games ? Any equation or data that can help? Or what characteristics a brain game should have ? I am getting interested on this and search internet a lot, but unfortunately I could not find the core structure of it. It will really a helpful for me if somebody can give some information. Thank you.

  Read the article

• Is it viable to make a port from a C++ application to Java through LLVM

  - by Javier Mr

  how viable is it to port a C++ application to Java bytecode using LLVM (I guess LLJVM)? The thing is that we currently have a process written in C++ but a new client has made mandatory to been able to run the program in a multiplatform way, using the Java Virtual Machine with obviously no native code (no JNI). The idea is to be able to take the generated jar and copy then to different systems (Linux, Win, 32 bits - 64 bits) and it should just work. Looking around looks like it is possible to compile C++ to LLVM IR code and then that code to java bytecode. There is no need of the generated code to be readable. I have test a bit with similar things using emscripten, this takes C++ code and compile it to JavaScript. The result is valid JS but totally unreadable (looks like assambler). Does anybody done a port of an application from C++ to Java bytecode using this tecnique? What problems could we face? Is a valid approach for production code? Note: I am aware that currently we have some non standard C++ and close source libraries, we are looking to removing this non standard code and all close source libraries and use Free Libre Open Source Software, so lets suppose all code is standard C++ code with all code available at compile time. Note: It is not an option to write portable C++ code and then compile it to the desired target platform, the compiled program must be mltiplatform thus the use of JVM (right now we are not looking in similar solutions but Python or other language base, but i would also like to heard about it)

  Read the article

• Top X tips to code & debug efficiently [closed]

  - by user1510230

  I'm starting a big Java project and I wanted to have some advices that could benefit us all. What are the X (X could be 5 / 10 / ... or even 100 :) most important tips to code and debug efficiently in general (and in particular with java / javascript) ? I'll start with some basic ones : Use functions everytime a portion of code is used more than twice. Try not to code features with more than 15 lines of code in one shot. Rather write 5 lines of code then check if they work correctly then write 5 more... and so on start with the outcome of the function and then code it backwards (bottom-top approach) ... Thanks everybody

  Read the article

< Previous Page | 59 60 61 62 63 64 65 66 67 68 69 70  | Next Page >