Search Results

Search found 34093 results on 1364 pages for 'database architecture'.

Page 147/1364 | < Previous Page | 143 144 145 146 147 148 149 150 151 152 153 154  | Next Page >

• Structure of a correctly implemented JTable with TableModel and Listeners?

  - by bamboocha

  I am pretty new to Java and its JTables and this is where I am struggling at the moment. I need to create a GUI which shows me results of a sql query like SELECT * FROM tblPeople WHERE name='Doe'. My idea was to create a a JFrame which displays a JTable with all found records. Besides this, I need to also implement some code to handle when a user is double clicking a record or selecting it by using his arrow keys (additional feature: pressing 12(e.g.) should select the 12th record). What is the best way to structure my program (what classes do I need and especially where do I store my logic)? I came up with structuring it the following way: Main.java ("view") SQLConnection.java PeopleTableModel.java (only stores and returns data given by the passed ResultSet, "model" inherits from DefaultTableModel) PeopleTable.java (stores basically all my logic including KeyListener and MouseListener, "controller", inherits from JTable) Are there better ways to achieve my goals? If so, what are they?

  Read the article

• Is 2 lines of push/pop code for each pre-draw-state too many?

  - by Griffin

  I'm trying to simplify vector graphics management in XNA; currently by incorporating state preservation. 2X lines of push/pop code for X states feels like too many, and it just feels wrong to have 2 lines of code that look identical except for one being push() and the other being pop(). The goal is to eradicate this repetitiveness,and I hoped to do so by creating an interface in which a client can give class/struct refs in which he wants restored after the rendering calls. Also note that many beginner-programmers will be using this, so forcing lambda expressions or other advanced C# features to be used in client code is not a good idea. I attempted to accomplish my goal by using Daniel Earwicker's Ptr class: public class Ptr<T> { Func<T> getter; Action<T> setter; public Ptr(Func<T> g, Action<T> s) { getter = g; setter = s; } public T Deref { get { return getter(); } set { setter(value); } } } an extension method: //doesn't work for structs since this is just syntatic sugar public static Ptr<T> GetPtr <T> (this T obj) { return new Ptr<T>( ()=> obj, v=> obj=v ); } and a Push Function: //returns a Pop Action for later calling public static Action Push <T> (ref T structure) where T: struct { T pushedValue = structure; //copies the struct data Ptr<T> p = structure.GetPtr(); return new Action( ()=> {p.Deref = pushedValue;} ); } However this doesn't work as stated in the code. How might I accomplish my goal? Example of code to be refactored: protected override void RenderLocally (GraphicsDevice device) { if (!(bool)isCompiled) {Compile();} //TODO: make sure state settings don't implicitly delete any buffers/resources RasterizerState oldRasterState = device.RasterizerState; DepthFormat oldFormat = device.PresentationParameters.DepthStencilFormat; DepthStencilState oldBufferState = device.DepthStencilState; { //Rendering code } device.RasterizerState = oldRasterState; device.DepthStencilState = oldBufferState; device.PresentationParameters.DepthStencilFormat = oldFormat; }

  Read the article

• How do I architect 2 plugins that share a common component?

  - by James

  I have an object that takes in data and spits out a transformed output, called IBaseItem. I also have two parsers, IParserA and IParserB. These parsers transform external data (in format dataA and dataB respectively) to a format usable by my IBaseItem (baseData). I want to create 2 systems, one that works with dataA and one that works with dataB. They will allow the user to enter data and match it to the right plugins/implementations and transform the data to outData. I want to write these traffic cops myself, but have other people provide the parsers and baseitem logic, and and as such am implementing these items as plugins (hence the use of interfaces). Other programmers can choose to implement 1 or both parsers. Q: How should I structure the way base items and parsers are associated, stored, and loaded into each of my programs? Class Relations: What I've Tried: Initially I though there should be a different dll for each of my 2 traffic cops, that each have a parser and baseitem in them. However, the duplication of baseitem logic doesn't seem right (especially if the base item logic changes). I then thought the base items could all have their own dll, and then somehow associate parsers and baseitems (guids?), but I don't know if implementing the overhead id/association is adding too much complexion.

  Read the article

• About shared (static) Members and its behavior

  - by Allende

  I just realized that I can access shared members from instances of classes (probably this is not correct, but compile and run), and also learn/discover that, I can modify shared members, then create a new instance and access the new value of the shared member. My question is, what happens to the shared members, when it comes back to the "default" value (class declaration), how dangerous is it do this ? is it totally bad ? is it valid in some cases ?. If you want to test my point here is the code (console project vb.net) that I used to test shared members, as you can see/compile/run, the shared member "x" of the class "Hello" has default value string "Default", but at runtime it changes it, and after creating a new object of that class, this object has the new value of the shared member. Module Module1 Public Class hello Public Shared x As String = "Default" Public Sub New() End Sub End Class Sub Main() Console.WriteLine("hello.x=" & hello.x) Dim obj As New hello() Console.WriteLine("obj.x=" & obj.x) obj.x = "Default shared memeber, modified in object" Console.WriteLine("obj.x=" & obj.x) hello.x = "Defaul shared member, modified in class" Console.WriteLine("hello.x=" & hello.x) Dim obj2 As New hello() Console.WriteLine("obj2.x=" & obj2.x) Console.ReadLine() End Sub End Module UPDATE: First at all, thanks to everyone, each answer give feedback, I suppose, by respect I should choose one as "the answer", I don't want to be offensive to anyone, so please don't take it so bad if I didn't choose you answer.

  Read the article

• Is component-based design an architectural pattern or design pattern?

  - by xEnOn

  When using the component-based paradigm in game development with engines like Unity, is component-based design an architectural pattern, or a design pattern? Can I even say that component-based design is my "main" architectural pattern for my game? I see architectural patterns as being more high-level than design pattern. The component-based design in game development's context (like with Unity engine) seems to fit as an architectural pattern to me. However, on some sites, I read that component-based design is a behavioural pattern, much like other behavioural design patterns, and not so much like an architectural pattern like MVC.

  Read the article

• Digital "Post It" notes for organizing content of sites/pages

  - by Alex

  We're restructuring our old intranet into a new one and are going through each site to find content and use our new standard structure/look-and-feel. Do you recommend a tool where you can do "digital Post-It" notes? It would provide a way to type some items on a "card" and be able to move it around and organize it quickly. Also, if you know of tools in general for this kind of task, please advise. Thank you.

  Read the article

• How do I create my own programming language and a compiler for it

  - by Dave

  I am thorough with programming and have come across languages including BASIC, FORTRAN, COBOL, LISP, LOGO, Java, C++, C, MATLAB, Mathematica, Python, Ruby, Perl, Javascript, Assembly and so on. I can't understand how people create programming languages and devise compilers for it. I also couldn't understand how people create OS like Windows, Mac, UNIX, DOS and so on. The other thing that is mysterious to me is how people create libraries like OpenGL, OpenCL, OpenCV, Cocoa, MFC and so on. The last thing I am unable to figure out is how scientists devise an assembly language and an assembler for a microprocessor. I would really like to learn all of these stuff and I am 15 years old. I always wanted to be a computer scientist some one like Babbage, Turing, Shannon, or Dennis Ritchie. I have already read Aho's Compiler Design and Tanenbaum's OS concepts book and they all only discuss concepts and code in a high level. They don't go into the details and nuances and how to devise a compiler or operating system. I want a concrete understanding so that I can create one myself and not just an understanding of what a thread, semaphore, process, or parsing is. I asked my brother about all this. He is a SB student in EECS at MIT and hasn't got a clue of how to actually create all these stuff in the real world. All he knows is just an understanding of Compiler Design and OS concepts like the ones that you guys have mentioned (ie like Thread, Synchronisation, Concurrency, memory management, Lexical Analysis, Intermediate code generation and so on)

  Read the article

• Rendering order in an Entity System

  - by Daedalus

  Say I use a basic ES approach, and also inside Systems I hold lists of all entities that Systems are required to process. How do I maintain this list of entities in desired rendering order, i.e. for a dumb 2D RenderingSystem? I saw this discussion, and what they suggest is to do something like Z ordering - what I would probably do is just to store a "layer" int in DrawableComponent and then, inside RenderingSystem, just sort entities by mentioned "layer" whenever the entity list for RenderingSystem changes. They also say we could just delete and recreate the entity whenever we want it on the top, but it seems too inflexible to me. How is this problem usually solved?

  Read the article

• Techniques for separating game model from presentation

  - by liortal

  I am creating a simple 2D game using XNA. The elements that make up the game world are what i refer to as the "model". For instance, in a board game, i would have a GameBoard class that stores information about the board. This information could be things such as: Location Size Details about cells on the board (occupied/not occupied) etc This object should either know how to draw itself, or describe how to draw itself to some other entity (renderer) in order to be displayed. I believe that since the board only contains the data+logic for things regarding it or cells on it, it should not provide the logic of how to draw things (separation of concerns). How can i achieve a good partitioning and easily allow some other entity to draw it properly? My motivations for doing so are: Allow multiple "implementations" of presentation for a single game entity Easier porting to other environments where the presentation code is not available (for example - porting my code to Unity or other game technology that does not rely on XNA).

  Read the article

• What is the difference between all-static-methods and applying a singleton pattern?

  - by shahensha

  I am making a database to store information about the users of my website (I am using stuts2 and hence Java EE technology). For the database I'll be making a DBManager. Should I apply singleton pattern here or rather make all it's methods static? I will be using this DBManager for basic things like adding, deleting and updating User profiles. Along with it, I'll use for all other querying purposes, for instance to find out whether a username already exists and to get all users for administrative purposes and stuff like that. My questions What is the benefit of singleton pattern? Which thing is most apt here? All static methods or a singleton pattern? Please compare both of them. regards shahensha P.S. The database is bigger than this. Here I am talking only about the tables which I'll be using for storing User Information.

  Read the article

• Multi-Threaded Pipelined Game Engine Data Synchronization Questions

  - by Douglas

  Let's say I'm setting up a worker pool based game engine with pipelining. Let's say I have 4 stages in my pipeline as such: Stage 1: Physics Stage 2: AI/Input Stage 3: Game Logic Stage 4: Rendering Now let's say that the physics detects a collision between a bullet and a character in stage 1. Two frames later the game logic may choose to remove that bullet from the simulation, however none of the other copies of the data for the other pipeline stages will get this information. How is this sort of thing and other things like it get handled? Do you generally make changes like this to every pipeline stage's data at the end of a frame?

  Read the article

• Structuring game world entities and their rendering objects

  - by keithjgrant

  I'm putting together a simple 2d tile-based game. I'm finding myself spinning circles on some design decisions, and I think I'm in danger of over-engineering. After all, the game is simple enough that I had a working prototype inside of four hours with fewer than ten classes, it just wasn't scalable or flexible enough for a polished game. My question is about how to structure flow of control between game entity objects and their rendering objects. Should each renderer have a reference to their entity or vice-versa? Or both? Should the entity be in control of calling the render() method, or be completely oblivious? I know there are several valid approaches here, but I'm kind of feeling decision paralysis. What are the pros and cons of each approach?

  Read the article

• xmpp flow -server, client and library

  - by Him

  My complete requirement is development of a chat engine - including server, clients etc. Currently I am working on things at my desktop only but once done, I have to host it; basically incorporate it with in a site for chatting purpose. So, now my problem is: I am not clear about how the actual data flow is? I have googled and read about xmpp (a book by Peter Andre) also but I am not clear about the flow and what are the actual requirements to do the above mentioned task. What I currently know is: 1) I need a server - so selected ejabberd 2) I need client - still not sure which one to use and one other doubt is how this client thing will work when deployed on some website for chatting purpose. 3) Some library - don't know which one and what is the purpose? Can anyone guide me?

  Read the article

• ORA- 01157 / Cant connect to database

  - by Tom

  Hi everyone, this is a follow up from this question. Let me start by saying that i am NOT a DBA, so i'm really really lost with this. A few weeks ago, we lost contact with one of our SID'S. All the other services are working, but this one in particular is not. What we got was this message when trying to connect ORA-01033: ORACLE initialization or shutdown in progress An attempt to alter database open ended up in ORA-01157: cannot identify/lock data file 6 - see DBWR trace file ORA-01110: data file 6: '/u01/app/oracle/oradata/xxx/xxx_data.dbf' I tried to shutdown / restart the database, but got this message. Total System Global Area 566231040 bytes Fixed Size 1220604 bytes Variable Size 117440516 bytes Database Buffers 444596224 bytes Redo Buffers 2973696 bytes Database mounted. ORA-01157: cannot identify/lock data file 6 - see DBWR trace file ORA-01110: data file 6: '/u01/app/oracle/oradata/xxx/xxx_data.dbf' When all continued the same, I erased the dbf files (rm xxx_data.dbf xxx_index.dbf), and recreated them using touch xxx_data.dbf. I also tried to recreate the tablespaces using `CREATE TABLESPACE DATA DATAFILE XXX_DATA.DBF` and got Database not open As I said, i don't know how bad this is, or how far i'm from gaining access to my database (well, to this SID at least, the others are working). I would imagine that a last resource would be to throw everything away, and recreating it, but I don't know how to, and I was hoping there's a less destructive solution. Any help will be greatly appreciated . Thanks in advance.

  Read the article

• Leveraging Code Across Platforms in Ever Bigger Games

  - by ashes999

  Summary: The same way that I continually build complex engines and libraries within a single platform and technology to allow me to build increasingly bigger and better games, how to continue this when development crosses into different platforms? If I switch platforms, how do I leverage past code and experiences? Games are hard to build. Big games are even harder to build. I've decided that to be able to make big games, I need to start building smaller games, and building up an asset base of code, assets (graphics, sounds), tools, and most importantly, game engines, so that I can eventually get there. One game at a time. Let me give an analogy. To build an MMO 3D RPG, I would approach this by building and releasing small games with increasingly more features. This could entail, for example: A simple 2D game A tile-based game A game with RPG elements (items, equipment, monsters, battle) A full-fledged RPG A 3D RPG The problem now is if I have to change platforms or tools, I don't know how to leverage past code-bases (and experience) to start with a mature product. Right now, I'm writing Silverlight (FlatRedBall) games. Let's say I stick with this for ten years, and then suddenly decide to write a PS6 game, which is in a different programming language entirely. Granted, I have ten years of game-development experience (and correspondingly ten years of professional software development experience from my day job) to back me up. But I would still like some way to transplant that 2D RPG engine into the new programming language, or else leverage it somehow. Is this even possible? What are my options?

  Read the article

• Making Class Diagram for MVC Pattern Project

  - by iMohammad

  I have a question about making a class diagram for an MVC based college senior project. If we have 2 actors of users in my system, lets say Undergrad and Graduate students are the children of abstract class called User. (Generalisation) Each actor has his own features. My question, in such case, do we need to have these two actors in separate classes which inherits from the abstract class User? even though, I'm going to implement them as roles using one Model called User Model ? I think you can see my confusion here. I code using MVC pattern, but I've never made a class diagram for this pattern. Thank you in advance!

  Read the article

• Service Layer - how broad should it be, and should it be used also on the local application?

  - by BornToCode

  Background: I need to build a main application with some operations (CRUD and more) (-in winforms), I need to make another application which will re-use some of the functions of the main application (-in webforms). I understood that using service layer is the best approach here. If I understood correctly the service should be calling the function on the BL layer (correct me if I'm wrong) The dilemma: In my main winform UI - should I call the functions from the BL, or from the service? (please explain why) Should I create a service for every single function on the BL even if I need some of the functions only in one UI? for example - should I create services for all the CRUD operations, even though I need to re-use only update operation in the webform? YOUR HELP IS MUCH APPRECIATED

  Read the article

• Basic game architechture best practices in Cocos2D on iOS

  - by MrDatabase

  Consider the following simple game: 20 squares floating around an iPhone's screen. Tapping a square causes that square to disappear. What's the "best practices" way to set this up in Cocos2D? Here's my plan so far: One Objective-c GameState singleton class (maintains list of active squares) One CCScene (since there's no menus etc) One CCLayer (child node of the scene) Many CCSprite nodes (one for each square, all child nodes of the layer) Each sprite listens for a tap on itself. Receive tap = remove from GameState Since I'm relatively new to Cocos2D I'd like some feedback on this design. For example I'm unsure of the GameState singleton. Perhaps it's unnecessary.

  Read the article

• Exchange 2007 - Mailbox Database Recovery

  - by Phrontiste

  Exchange 2007 edb Can we restore Exchange edb (First storage group\mailbox database.edb) to another exchange server ? Do I just copy the edb to the new exchange server and delete the first storage group\mailbox database.edb and replace it with this one ? How can I get all the mailboxes from that (old) mailbox database.edb ? I had a exchange 2007 server with 10 mailboxes, I have installed exchange on another machine and was thinking if I can do the above ? or is there any way I can get all the mailboxes from that edb (old mailbox database) and import them into the new one. I have deleted the old exchange install I had (these are test machines) What are the steps required to get the DB working on the new machine ? Also, I am confused about the recovery storage group ? I can mount a mailbox database in recovery storage group, but when I try to get mailbox out of it, it won't match any thing ? can someone please assist in understanding RSG and how to restore the OLD mailbox database. thanks and regards Phrontiste

  Read the article

• Develop for Desktop and mobile use?

  - by ran2

  I am in the very beginning of developing an app / desktop program. I want it to be cross-platform and possibly also as a tablet version (preferably Android Icecream sandwich). Note that I need to run it offline. I thought about the following approaches: ADOBE Air, since I do not need much performance. Plus I did some web programming in the past which might be of some use. Afaik it would run on OS X and Windows and should run on mobile OSes, too. Qt. Found some nice Qt based desktop recently and read it also works on android. Plus I like the SDK. HTML5 / JS. Again my web background should help me here. I wont need no sever side scripts, thus it should work without installing anything but a browser. How easy could this be converted into an Android app? There might be a plethora of other (better) ways to do it, but I haven't thought of them yet. Can you help out? How would you create such an application. Would it be better to do some pure desktop client and then create tablet versions? Would you rather start to create a website and worry later on how to turn into an app?

  Read the article

• How should I handle using two databases with a legacy PHP application?

  - by Toby Allen

  I have a legacy PHP application that was written in 2004 and uses MSSQL as a database backend. At this stage MSSQL is still supported by PHP but only just via a Microsoft driver. I have looked at converting to mysql via automated tools, which work quite well, but I have quite complex views which need a lot of individual work to convert. I don't have a great deal of time to do this. Many tools I wish to use and frameworks I would like to move the application to, don't support MSSQL, so I was considering adding new features using a new mysql database and wondered if anyone had opinions on the pros and cons of using two seperate database backends in a single application?

  Read the article

• Do you leverage the benefits of the open-closed principle?

  - by Kaleb Pederson

  The open-closed principle (OCP) states that an object should be open for extension but closed for modification. I believe I understand it and use it in conjunction with SRP to create classes that do only one thing. And, I try to create many small methods that make it possible to extract out all the behavior controls into methods that may be extended or overridden in some subclass. Thus, I end up with classes that have many extension points, be it through: dependency injection and composition, events, delegation, etc. Consider the following a simple, extendable class: class PaycheckCalculator { // ... protected decimal GetOvertimeFactor() { return 2.0M; } } Now say, for example, that the OvertimeFactor changes to 1.5. Since the above class was designed to be extended, I can easily subclass and return a different OvertimeFactor. But... despite the class being designed for extension and adhering to OCP, I'll modify the single method in question, rather than subclassing and overridding the method in question and then re-wiring my objects in my IoC container. As a result I've violated part of what OCP attempts to accomplish. It feels like I'm just being lazy because the above is a bit easier. Am I misunderstanding OCP? Should I really be doing something different? Do you leverage the benefits of OCP differently? Update: based on the answers it looks like this contrived example is a poor one for a number of different reasons. The main intent of the example was to demonstrate that the class was designed to be extended by providing methods that when overridden would alter the behavior of public methods without the need for changing internal or private code. Still, I definitely misunderstood OCP.

  Read the article

• MQTT, GWT, ActiveMQ stack to bring jms to the browser

  - by scphantm

  I am in the preliminary stages of architecting a legacy replacement project. They already have sub half second performance on their green screens and they want the same on their web app. We have a 390 mainframe that can handle anything we throw at it but they don't have a good jvm for it, so we have two tiers of websphere servers between the mainframe and the browser, The ui server, and the bl server. For the ui, I'm leaning towards GWT. But one thing that I think would seal the deal is to add messaging capabilities to the browser. The idea is say you click on a link that displays a second panel of information, instead of the classic GWT where it triggers a GWT-RPC call to the ui server, the ui server routs it to the bl server, the bl sends it to the mainframe and back out, it drops an MQTT message directly to the bl server or directly to the mainframe. Say writes go to the bl, reads go to the mainframe. This is an easy enough thing in classic jms because you can issue a message that has an expected response. Then have your callback ready to get the resonse. But from what I'm reading so far. It looks like mqtt doesn't have that. It looks like it's strictly fire and forget, which would make it really tough to come up with a way to get a response back to the workstation that called it. Am I right here? Has anyone tried this stack before with gwt.

  Read the article

• Database Insider Newsletter: February 2011 Edition Available

  - by jenny.gelhausen

  The February edition of the Database Insider Newsletter is now available. This edition covers the upcoming IOUG's Day of Real World Performance Tour What's coming for Collaborate 2011 How Oracle helps you steer clear of security pitfalls and much more... Enjoy! var gaJsHost = (("https:" == document.location.protocol) ? "https://ssl." : "http://www."); document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E")); try { var pageTracker = _gat._getTracker("UA-13185312-1"); pageTracker._trackPageview(); } catch(err) {}

  Read the article

• Oracle NoSQL Database Using FusionIO ioDrive2

  - by Charles Lamb

  We ran some benchmarks using FusionIO ioDrive2 SSD drives and Oracle NoSQL Database. FusionIO has published a whitepaper with the results of the benchmarks. "Results of testing showed that using an ioDrive2 for data delivered nearly 30 times more operations per second than a 300GB 10k SAS disk on a 90 percent read and 10 percent write workload and nearly eight times more operations per second on a 50 percent read and 50 percent write workload. Equally impressive, an ioDrive2 reduced latency over 700 percent (seven times) on inserts in a 90 percent read and 10 percent write workload and over 5800 percent (58 times) on reads in a 50 percent read and 50 percent write workload."

  Read the article

< Previous Page | 143 144 145 146 147 148 149 150 151 152 153 154  | Next Page >