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  • Sprite sorting issues

    - by TheBroodian
    I apologize for the vague title, I'm not sure how else to phrase this problem. I am using tIDE to assist me in my game's world development. To give a dynamic effect to map layers within tIDE, it has events that can be wired up to draw sprites before or after the draw of layers, to create foreground or background effects during runtime. This all works fine and well, however, the only way that I understand that this works, is by calling tIDE's internal spritebatch to create this effect. This creates a problem for me, because within tIDE's source code, its spritebatch's call block is set to SpriteSortMode.Deferred, and my characters have particle elements that I would like to draw in front of and behind themselves, via a drawdepth value. I can use a separate instance of spritebatch and call my character's draw method, and set sprite sorting there, but then my character is drawn ontop of all layers in my tIDE map. Which is even worse to me than my particles not being drawn as I want them to be. So, in summary, I want all of my crap to work, but at the moment the only way I can figure to do that is to ghetto rig the spritebatch within my characters' draw methods by calling a spritebatch.End();, then starting a new call to Begin() with SpriteSortMode.BackToFront, doing all of my characters' draw logic, and then calling another spritebatch.End(); followed once again by a new spritebatch.Begin(). Obviously that is pretty undesirable, but I don't know any other feasible alternatives. Anybody got any wisdom they could impart unto me as to how I could handle this?

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  • Adding delay between damage

    - by iQue
    I have a bunch of enemies chasing my main-character, and if they intersect I want them to damage him and that's all good. The problem is that right now they damage him as long as they stand around him, every frame! and since it gets called every frame my character's HP reaches 0 almost instantly. I've tried adding delay and I've tried a timertask, but can't get it to work. This is the code I use to check for intersection: private void checkCollision(Canvas canvas) { synchronized (getHolder()) { Rect h1 = happy.getBounds(); for (int i = 0; i < enemies.size(); i++) { for (int j = 0; j < bullets.size(); j++) { Rect b1 = bullets.get(j).getBounds(); Rect e1 = enemies.get(i).getBounds(); if (b1.intersect(e1)) { enemies.get(i).damageHP(5); bullets.remove(j); } if(e1.intersect(h1)){ happy.damageHP(5); // this is the statement that needs some sort of delay, I want them to damage him every 2 seconds they intersect him. } if(enemies.get(i).getHP() <= 0){ enemies.get(i).death(canvas, enemies); score.incScore(5); break; } if(happy.getHP() <= 0){ score.incScore(-50); //end-screen } } } } } If anyone knows the logic to do this please do tell.

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  • Designing a system with different business rules for different customers

    - by user1595846
    My company is rewriting our proprietary business application. The current architecture is poorly done and inflexible. It is coded more procedural oriented as opposed to object oriented. It has become difficult to maintain. Our system is a web application written in .Net Webforms. I am considering ASP.Net MVC for the rewrite. We intend to rewrite it with a good, solid architecture with the goal of maintainability and reusable classes for some of our other systems and services. We would also like the system to be customizable for different customers in the event that we market the system. I am considering redesigning the system based on the layered architecture (Presentation, Business, Data Access layers) described in the Microsoft Patterns and Practices Application Architecture Guide. http://msdn.microsoft.com/en-us/library/ff650706.aspx Hopefully this isn't too open ended, but how would you recommend allowing for different business logic/rules for different customers? I'm aware of Windows Workflow Foundation, but from what I've read about it, it seems many business rules could be too complicated to handle there. Also, Can anyone point me to where I can download an example of a .net solution that is based on the Application Architecture Guide? I have already downloaded the Layered Architecture Solution Guidance and the Expense Sample on codeplex. I was looking for something a bit larger and more robust that I could step through the code and see how it works. If you feel there are better architectures to base our redesign on please feel free to share. I appreciate your help!

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  • how to architect this to make it unit testable

    - by SOfanatic
    I'm currently working on a project where I'm receiving an object via web service (WSDL). The overall process is the following: Receive object - add/delete/update parts (or all) of it - and return the object with the changes made. The thing is that sometimes these changes are complicated and there is some logic involved, other databases, other web services, etc. so to facilitate this I'm creating a custom object that mimics the original one but has some enhanced functionality to make some things easier. So I'm trying to have this process: Receive original object - convert/copy it to custom object - add/delete/update - convert/copy it back to original object - return original object. Example: public class Row { public List<Field> Fields { get; set; } public string RowId { get; set; } public Row() { this.Fields = new List<Field>(); } } public class Field { public string Number { get; set; } public string Value { get; set; } } So for example, one of the "actions" to perform on this would be to find all Fields in a Row that match a Value equal to something, and update them with some other value. I have a CustomRow class that represents the Row class, how can I make this class unit testable? Do I have to create an interface ICustomRow to mock it in the unit test? If one of the actions is to sum all of the Values in the Fields that have a Number equal to 10, like this function, how can design the custom class to facilitate unit tests. Sample function: public int Sum(FieldNumber number) { return row.Fields.Where(x => x.FieldNumber.Equals(number)).Sum(x => x.FieldValue); } Am I approaching this the wrong way?

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  • Partner Webcast - Oracle Business Process Management: What’s new in Oracle BPM 11.1.1.7.0 - 04 July 2013

    - by Thanos
    Business processes are at the heart of what makes or breaks a business—and what differentiates it from the competition. Business processes that deliver operational efficiency, business visibility, excellent customer experience, and agility give the enterprise an edge over the competition. Business managers need process management tools that enable them to make impactful changes. Oracle has been always a leader in this area and the new version of Oracle BPM 11g takes that even further by providing complete web based process modeling, simulation and implementation including designing the user interface and business logic. That provides business users with ability to take complete control over the business processes without sacrificing the vast service integration capabilities delivered traditionally by IT using SOA approach. Oracle Business Process Management is the industry's most complete and business user-friendly BPM solution. Register today for this webcast and find out more on the latest and most exciting new features which are now available in Oracle BPM Suite. Agenda Introduction do Oracle BPM 11g Exciting new features in this release Revamped Process Composer Simulations Web Forms Process Player Adaptive Case Management Instance Revisioning Other features Demonstration Q&A Delivery Format This FREE online LIVE eSeminar will be delivered over the Web. Registrations received less than 24hours prior to start time may not receive confirmation to attend. Duration: 1 hour Register Now! For any questions please contact us at [email protected] Visit our ISV Migration Center blog & Facebook Page or Follow us @oracleimc  to learn more on Oracle Technologies, upcoming partner webcasts and events. Existing content available YouTube - SlideShare - Oracle Mix

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  • Partner Webcast – Oracle Weblogic 12c for New Projects - 07 Nov 2013

    - by Thanos Terentes Printzios
    Fast-growing organizations need to stay agile in the face of changing customer, business or market requirements. Oracle WebLogic Server 12c is the industry's best application server platform that allows you to quickly develop and deploy reliable, secure, scalable and manageable enterprise Java EE applications.WebLogic Server Java EE applications are based on standardized, modular components. WebLogic Server provides a complete set of services for those modules and handles many details of application behavior automatically, without requiring programming. New project applications are created by Java programmers, Web designers, and application assemblers. Programmers and designers create modules that implement the business and presentation logic for the application. Application assemblers assemble the modules into applications that are ready to deploy on WebLogic Server. Build and run high-performance enterprise applications and services with Oracle WebLogic Server 12c, available in three editions to meet the needs of traditional and cloud IT environments. Join us, in this webcast, as we will show you how WebLogic Server 12c helps you building and deployingenterprise Java EE applications with support for new features for lowering cost of operations, improving performance, enhancing scalability. Agenda Oracle WebLogic Server Introduction Application Development on WebLogic Using Java EE Overview of the Application Deployment Process Monitoring Application Performance Q&A November 07th, 2013 -  9am UTC/11am EET Delivery FormatThis FREE online LIVE eSeminar will be delivered over the Web. Registrations received less than 24hours prior to start time may not receive confirmation to attend. Duration: 1 hour REGISTER NOW For any questions please contact us at partner.imc-AT-beehiveonline.oracle-DOT-com Stay Connected Oracle Newsletters

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  • Question on methods in Object Oriented Programming

    - by mal
    I’m learning Java at the minute (first language), and as a project I’m looking at developing a simple puzzle game. My question relates to the methods within a class. I have my Block type class; it has its many attributes, set methods, get methods and just plain methods. There are quite a few. Then I have my main board class. At the moment it does most of the logic, positioning of sprites collision detection and then draws the sprites etc... As I am learning to program as much as I’m learning to program games I’m curious to know how much code is typically acceptable within a given method. Is there such thing as having too many methods? All my draw functionality happens in one method, should I break this into a few ‘sub’ methods? My thinking is if I find at a later stage that the for loop I’m using to cycle through the array of sprites searching for collisions in the spriteCollision() method is inefficient I code a new method and just replace the old method calls with the new one, leaving the old code intact. Is it bad practice to have a method that contains one if statement, and place the call for that method in the for loop? I’m very much in the early stages of coding/designing and I need all the help I can get! I find it a little intimidating when people are talking about throwing together a prototype in a day too! Can’t wait until I’m that good!

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  • List all BPM Processes for a user

    - by kasriniv
    Hello, Happy to start contributing to this blog..  The title of the blog is probably deceptively simple and warrants an elaboration. Customized BPM workspaces/user interfaces are a fairly common requirement. One of our marquee customers in the online stock trading business, envisioned this user interaction for their BPM application: User logs in to the internal portal Use will have list of roles which he is granted as a drop down list Once user selects the role, a list of processes which user is part of appear. Logged in user can be part of any swimlane role of the process This can be a fairly common/reasonable user-UI interaction pattern. 1. and 2. are easily achievable and hence the subject matter of this blog is the requirement in 3. Objective: Given a username and a role, list all the BPM processes that the user is part of, in any swimlane of any process. Here is quick overview of the major steps/logic in the code: Intialize workflow/BPM  context as usual Get a handle on InstanceQueryService(getInstanceQueryService), InstanceManagementService,        ProcessMetadataService and ProcessModelService List all Processes for that bpmcontext (listProcessMetadataSumary) and get Granted roles to that user For each of the processes [method  getAccessibleProcesss(ProcessMetadataSummary, Set)]for each of the lanes in the process, check if the role granted to the user, matches the roleName for that swimlane. If so, add to output. Notes: The usual caveats apply including BPM APIs are subject to change.  JDeveloper method introspection is your better friend than API documentation :-)... (I am going to try upload the source code  and if it doesnt work, will follow this blog up with the corresponding source code.) Hope this helps.  Ack: Yogesh K, BPM Dev team.

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  • Deploying my first website!

    - by test
    I have built a data driven website - an asp.net website, using the entity framework. In my solution I have 4 projects - the web application PresentationLayer, and 3 class libraries - Data Layer, Business and Common Layer. In one of these libraries, Common Layer I have my Model (MyModel.edmx). I have always tested my application on Cassini - Asp.Net Development Server. I have never touched IIS in my life. I bought a domain and hosting on go daddy. My logic tells me to grab my four folders (1 for each layer) and simply move them to the root folder. But I know I'm wrong since then the home page would be mywebsite.org/presentationlayer/default.aspx and second of all I start getting a bunch of errors where files do not load or they are not found. I also know that I need to manage the web.config but I don't have any experience where to start. I'm not sure if this is a problem but I also have a web service included in my presentation layer.

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  • Storing editable site content?

    - by hmp
    We have a Django-based website for which we wanted to make some of the content (text, and business logic such as pricing plans) easily editable in-house, and so we decided to store it outside the codebase. Usually the reason is one of the following: It's something that non-technical people want to edit. One example is copywriting for a website - the programmers prepare a template with text that defaults to "Lorem ipsum...", and the real content is inserted later to the database. It's something that we want to be able to change quickly, without the need to deploy new code (which we currently do twice a week). An example would be features currently available to the customers at different tiers of pricing. Instead of hardcoding these, we read them from database. The described solution is flexible but there are some reasons why I don't like it. Because the content has to be read from the database, there is a performance overhead. We mitigate that by using a caching scheme, but this also adds some complexity to the system. Developers who run the code locally see the system in a significantly different state compared to how it runs on production. Automated tests also exercise the system in a different state. Situations like testing new features on a staging server also get trickier - if the staging server doesn't have a recent copy of the database, it can be unexpectedly different from production. We could mitigate that by committing the new state to the repository occasionally (e.g. by adding data migrations), but it seems like a wrong approach. Is it? Any ideas how best to solve these problems? Is there a better approach for handling the content that I'm overlooking?

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  • Creating shooting arrow class [on hold]

    - by I.Hristov
    OK I am trying to write an XNA game with one controllable by the player entity, while the rest are bots (enemy and friendly) wondering around and... shooting each other from range. Now the shooting I suppose should be done with a separate class Arrow (for example). The resulting object would be the arrow appearing on screen moving from shooting entity to target entity. When target is reached arrow is no longer active, probably removed from the list. I plan to make a class with fields: Vector2 shootingEntity; Vector2 targetEntity; float arrowSpeed; float arrowAttackSpeed; int damageDone; bool isActive; Then when enemy entities get closer than a int rangeToShoot (which each entity will have as a field/prop) I plan to make a list of arrows emerging from each entity and going to the closest opposite one. I wonder if that logic will enable me later to make possible many entities to be able to shoot independently at different enemy entities at the same time. I know the question is broad but it would be wise to ask if the foundations of the idea are correct.

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  • MVC pattern synchronisation

    - by Hariprasad
    I am facing a problem in synchronizing my model and view threads I have a view which is table. In it, user can select a few rows. I update the view as soon as the user clicks on any row since I don't want the UI to be slow. This updating is done by a logic which runs in the controller thread below. At the same time, the controller will update the model data too, which takes place in a different thread. i.e., controller puts the query in a queue, which is then executed by the model thread - which is a single-threaded interface. As soon as the query executes, controller will get a signal. Now, In order to keep the view and model synchronized, I will update the view again based on the return value of the query (the data returned by model) - even though I updated the view already for that user action. But, I am facing issues because, its taking a lot of time for the model to return the result, by that time user would have performed multiple clicks. So, as a result of updating the view again based on the information from model, the view sometimes goes back to the state in which the previous clicks were made (Suppose user clicks thrice on different rows. I update the view as soon as the click happens. Also, I update the view when I get data back from the model - which is supposed to be same as the already updated state of the view. Now, when the user clicks third time, I get data for the first click from model. As a result, view goes back to a state which is generated by the first click) Is there any way to handle such a synchronization issue?

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  • Keeping a domain model consistent with actual data

    - by fstuijt
    Recently domain driven design got my attention, and while thinking about how this approach could help us I came across the following problem. In DDD the common approach is to retrieve entities (or better, aggregate roots) from a repository which acts as a in-memory collection of these entities. After these entities have been retrieved, they can be updated or deleted by the user, however after retrieval they are essentially disconnected from the data source and one must actively inform the repository to update the data source and make is consistent again with our in-memory representation. What is the DDD approach to retrieving entities that should remain connected to the data source? For example, in our situation we retrieve a series of sensors that have a specific measurement during retrieval. Over time, these measurement values may change and our business logic in the domain model should respond to these changes properly. E.g., domain events may be raised if a sensor value exceeds a predefined threshold. However, using the repository approach, these sensor values are just snapshots, and are disconnected from the data source. Does any of you have an idea on how to solve this following the DDD approach?

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  • Branding/Restricting a Software by License/Serial

    - by Sid
    I have made a POS System for a client of mine using MS Access Server-Client approach. He asked me to brand his software to allow only a certain "number" of users (cashiers) to access the POS System, and must be determined to the license his client will buy. EX: 10 User License = 10 Cashiers ( not necessarily 10 users, it can be 30 users, shifting) = it means 10 PCs will be installed with the client software I made. How and where do I put the logic that will determine if it is licensed or not. What I have done: I have created a serial key generator using Name. Problem is it can be duplicated once you give than name+serial combination, it would still work. I am counting the number of users logged at a time. This could be problematic as I am using MSAccess and not MSSQL. I have scrapped this idea, He also asked me if I could just put serial+mac address combination. That I could do but he will have a hard time implementing it and selling it if he needs the mac address of every computers to be installed with my POS. I am at lost on what can I do. Would like to ask for tips and suggestions. Thank you.

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  • Do you write unit tests for all the time in TDD?

    - by mcaaltuntas
    I have been designing and developing code with TDD style for a long time. What disturbs me about TDD is writing tests for code that does not contain any business logic or interesting behaviour. I know TDD is a design activity more than testing but sometimes I feel it's useless to write tests in these scenarios. For example I have a simple scenario like "When user clicks check button, it should check file's validity". For this scenario I usually start writing tests for presenter/controller class like the one below. @Test public void when_user_clicks_check_it_should_check_selected_file_validity(){ MediaService service =mock(MediaService); View view =mock(View); when(view.getSelectedFile).thenReturns("c:\\Dir\\file.avi"); MediaController controller =new MediaController(service,view); controller.check(); verify(service).check("c:\\Dir\\file.avi"); } As you can see there is no design decision or interesting code to verify behaviour. I am testing values from view passed to MediaService. I usually write but don't like these kind of tests. What do yo do about these situations ? Do you write tests for all the time ? UPDATE : I have changed the test name and code after complaints. Some users said that you should write tests for the trivial cases like this so in the future someone might add interesting behaviour. But what about “Code for today, design for tomorrow.” ? If someone, including myself, adds more interesting code in the future the test can be created for it then. Why should I do it now for the trivial cases ?

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  • Is there any kind of established architecture for browser based MMO games?

    - by black_puppydog
    I am beginning the development of a broser based game in which players take certain actions at any point in time. Big parts of gameplay will be happening in real life and just have to be entered into the system. I believe a good kind of comparison might be a platform for managing fantasy football, although I have virtually no experience playing that, so please correct me if I am mistaken here. The point is that some events happen in the program (i.e. on the server, out of reach for the players) like pulling new results from some datasource, starting of a new round by a game master and such. Other events happen in real life (two players closing a deal on the transfer of some team member or whatnot - again: have never played fantasy football) and have to be entered into the system. The first part is pretty easy since the game masters will be "staff" and thus can be trusted to a certain degree to not mess with the system. But the second part bothers me quite a lot, especially since the actions may involve multiple steps and interactions with different players, like registering a deal with the system that then has to be approved by the other party or denied and passed on to a game master to decide. I would of course like to separate the game logic as far as possible from the presentation and basic form validation but am unsure how to do this in a clean fashion. Of course I could (and will) put some effort into making my own architectural decisions and prototype different ideas. But I am bound to make some stupid mistakes at some point, so I would like to avoid some of that by getting a little "book smart" beforehand. So the question is: Is there any kind of architectural works that I can read up on? Papers, blogs, maybe design documents or even source code? Writing this down this seems more like a business application with business rules, workflows and such... Any good entry points for that?

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  • Do the benefits of Resin/Quercus outweigh the overhead?

    - by Craige
    Lately, I've been looking more and more into Resin + Quercus as a technology to develop an application of mine. The reason I started looking into it was that this application has high reporting needs, a lot of which cannot (or realistically, should not) be created in real-time. Java would offer a nice backend to queue and generate reports. Also, with Quercus I would be able to develop my data models in Hibernate, and use them "from PHP", thus effectively stretching these models across front and back-end. This same concept would also apply to any front/back-end common business logic, which could be developed in Java libraries. Now, the downside is that whichever front-end (PHP) MVC Framework I choose (my goal was Symfony 2), it is unlikely to work without some heavy modification, if it can work at all. Quercus is a pretty close implementation of PHP, and is supposed to be compatible with PHP5.3, so namespaces and closures SHOULDN'T be a problem, but when I tried to run an existing Symfony 1.4 app, I failed miserably. So, my question to you is, do you think the benefits of Resin + Quercus outweigh the overhead of using a not-so-perfect/stable implementation of PHP? If this were your application, and your goal was and end-product, rather than educational purposes, what would you decide?

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  • Binding in the view or the controller?

    - by da_b0uncer
    I've seen 2 different approaches with MVC on the web. One, like in ExtJS, is to bind the callbacks to the view via the controller. Finding every element on the view and adding the functionallity. The other, like in angular.js and in the lift-framework server-side, too, is to bind in the views and just write the functionallity in the controller. Which is better and cleaner? The ExtJS approach has dumb views and all the logic in the controller. Which seems clean to me. I had problems with global IDs for GUI-elements or relative navigation to GUI-elements in this approach. When I changed the view, the controller couldn't find the buttons anymore or I had multiple instances of one button with the same ID on a single application, because of the global ID. But I solved this with IDs that are only global in a view and can be on the application multiple times. So I could mess with the (dumb) views layout and design and the functionallity wouldn't break. The angular.js approach with the bindings in the view don't has the problem with global IDs. Also, the person who changes something in the view layout has to know the IDs anyway, so the controller can put the data at the right spot. So if I write <a ng-click="doThis()" /> for angular.js and implement doThis() or <a lid="buttonwhichdoesthis" /> for extjs and find the element with the local id and add doThis() as handler on the controller side, seems to be not so different. The only thing is, the second one has one more layer of indirection, which seems cleaner. The first one seems somehow to cost less effort.

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  • Learning how to design knowledge and data flow [closed]

    - by max
    In designing software, I spend a lot of time deciding how the knowledge (algorithms / business logic) and data should be allocated between different entities; that is, which object should know what. I am asking for advice about books, articles, presentations, classes, or other resources that would help me learn how to do it better. I code primarily in Python, but my question is not really language-specific; even if some of the insights I learn don't work in Python, that's fine. I'll give a couple examples to clarify what I mean. Example 1 I want to perform some computation. As a user, I will need to provide parameters to do the computation. I can have all those parameters sent to the "main" object, which then uses them to create other objects as needed. Or I can create one "main" object, as well as several additional objects; the additional objects would then be sent to the "main" object as parameters. What factors should I consider to make this choice? Example 2 Let's say I have a few objects of type A that can perform a certain computation. The main computation often involves using an object of type B that performs some interim computation. I can either "teach" A instances what exact parameters to pass to B instances (i.e., make B "dumb"); or I can "teach" B instances to figure out what needs to be done when looking at an A instance (i.e., make B "smart"). What should I think about when I'm making this choice?

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  • Dealing with numerous, simultaneous sounds in unity

    - by luxchar
    I've written a custom class that creates a fixed number of audio sources. When a new sound is played, it goes through the class, which creates a queue of sounds that will be played during that frame. The sounds that are closer to the camera are given preference. If new sounds arrive in the next frame, I have a complex set of rules that determines how to replace the old ones. Ideally, "big" or "important" sounds should not be replaced by small ones. Sound replacement is necessary since the game can be fast-paced at times, and should try to play new sounds by replacing old ones. Otherwise, there can be "silent" moments when an old sound is about to stop playing and isn't replaced right away by a new sound. The drawback of replacing old sounds right away is that there is a harsh transition from the old sound clip to the new one. But I wonder if I could just remove that management logic altogether, and create audio sources on the fly for new sounds. I could give "important" sounds more priority (closer to 0 in the corresponding property) as opposed to less important ones, and let Unity take care of culling out sound effects that exceed the channel limit. The only drawback is that it requires many heap allocations. I wonder what strategy people use here?

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  • Preferred way for dealing with customer-defined data in enterprise application

    - by Axarydax
    Let's say that we have a small enterprise web (intranet) application for managing data for car dealers. It has screens for managing customers, inventory, orders, warranties and workshops. This application is installed at 10 customer sites for different car dealers. First version of this application was created without any way to provide for customer-specific data. For example, if dealer A wanted to be able to attach a photo to a customer, dealer B wanted to add e-mail contact to each workshop, and dealer C wanted to attach multiple PDF reports to a warranty, each and every feature like this was added to the application, so all of the customers received everything on new update. However, this will inevitably lead to conflicts as the number of customers grow as their usage patterns are unique, and if, for instance, a specific dealer requested to have an ability to attach (for some reason) a color of inventory item (and be able to search by this color) as a required item, others really wouldn't need this feature, and definitely will not want it to be a required item. Or, one dealer would like to manage e-mail contacts for their employees on a separate screen of the application. I imagine that a solution for this is to use a kind of plugin system, where we would have a core of the application that provides for standard features like customers, inventory, etc, and all of the customer's installed plugins. There would be different kinds of plugins - standalone screens like e-mail contacts for employees, with their own logic, and customer plugin which would extend or decorate inventory items (like photo or color). Inventory (customer,order,...) plugins would require to have installation procedure, hooks for plugging into the item editor, item displayer, item filtering for searching, backup hook and such. Is this the right way to solve this problem?

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  • Do cross reference database tables have a place in domain driven design?

    - by Mike Cellini
    First some background. Let's say we have a system where a customer is placing an order in a web interface. The items that customer is ordering can priced in various ways. Sometimes including the cost of delivery and sometimes not at all. That pricing effectively depends on a variety of factors including the vendor's own pricing model, that vendor's individual contracts with customers as well as that vendor's contracts with its own suppliers. Let's assume that once a customer places an order for a particular item and chooses a contract if any, the method of delivery can be determined by variables on those contracts. Those delivery methods also live in their own table in the database and have various properties consumed downstream. It makes sense that a cross reference or lookup table would store that information. That table would be loaded into the domain and could then be used to apply the appropriate delivery method while processing the order. Does this make sense in the context of domain driven design? Or is my thinking too relational? Is this logic that should be built into it's own class/method (I mean beyond apply the cross reference table data)?

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  • Integrating Amazon EC2 in Java via NetBeans IDE

    - by Geertjan
    Next, having looked at Amazon Associates services and Amazon S3, let's take a look at Amazon EC2, the elastic compute cloud which provides remote computing services. I started by launching an instance of Ubuntu Server 14.04 on Amazon EC2, which looks a bit like this in the on-line AWS Management Console, though I whitened out most of the details: Now that I have at least one running instance available on Amazon EC2, it makes sense to use the services that are integrated into NetBeans IDE:  I created a new application with one class, named "AmazonEC2Demo". Then I dragged the "describeInstances" service that you see above, with the mouse, into the class. Then the IDE automatically created all the other files you see below, i.e., 4 Java classes and one properties file: In the properties file, register the access ID and secret keys. These are read by the other generated Java classes. Signing and authentication are done automatically by the code that is generated, i.e., there's nothing generic you need to do and you can immediately begin working on your domain-specific code. Finally, you're now able to rewrite the code in "AmazonEC2Demo" to connect to Amazon EC2 and obtain information about your running instance: public class AmazonEC2Demo { public static void main(String[] args) { String instanceId1 = "i-something"; RestResponse result; try { result = AmazonEC2Service.describeInstances(instanceId1); System.out.println(result.getDataAsString()); } catch (IOException ex) { Logger.getLogger(AmazonEC2Demo.class.getName()).log(Level.SEVERE, null, ex); } } } From the above, you'll receive a chunk of XML with data about the running instance, it's name, status, dates, etc. In other words, you're now ready to integrate Amazon EC2 features directly into the applications you're writing, without very much work to get started. Within about 5 minutes, you're working on your business logic, rather than on the generic code that anyone needs when integrating with Amazon EC2.

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  • How do you plan your asynchronous code?

    - by NullOrEmpty
    I created a library that is a invoker for a web service somewhere else. The library exposes asynchronous methods, since web service calls are a good candidate for that matter. At the beginning everything was just fine, I had methods with easy to understand operations in a CRUD fashion, since the library is a kind of repository. But then business logic started to become complex, and some of the procedures involves the chaining of many of these asynchronous operations, sometimes with different paths depending on the result value, etc.. etc.. Suddenly, everything is very messy, to stop the execution in a break point it is not very helpful, to find out what is going on or where in the process timeline have you stopped become a pain... Development becomes less quick, less agile, and to catch those bugs that happens once in a 1000 times becomes a hell. From the technical point, a repository that exposes asynchronous methods looked like a good idea, because some persistence layers could have delays, and you can use the async approach to do the most of your hardware. But from the functional point of view, things became very complex, and considering those procedures where a dozen of different calls were needed... I don't know the real value of the improvement. After read about TPL for a while, it looked like a good idea for managing tasks, but in the moment you have to combine them and start to reuse existing functionality, things become very messy. I have had a good experience using it for very concrete scenarios, but bad experience using them broadly. How do you work asynchronously? Do you use it always? Or just for long running processes? Thanks.

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  • Call DB Stored Procedure using @NamedStoredProcedureQuery Injection

    - by anwilson
    Oracle Database Stored Procedure can be called from EJB business layer to perform complex DB specific operations. This approach will avoid overhead from frequent network hits which could impact end-user result. DB Stored Procedure can be invoked from EJB Session Bean business logic using org.eclipse.persistence.queries.StoredProcedureCall API. Using this approach requires more coding to handle the Session and Arguments of the Stored Procedure, thereby increasing effort on maintenance. EJB 3.0 introduces @NamedStoredProcedureQuery Injection to call Database Stored Procedure as NamedQueries. This blog will take you through the steps to call Oracle Database Stored Procedure using @NamedStoredProcedureQuery.EMP_SAL_INCREMENT procedure available in HR schema will be used in this sample.Create Entity from EMPLOYEES table.Add @NamedStoredProcedureQuery above @NamedQueries to Employees.java with definition as given below - @NamedStoredProcedureQuery(name="Employees.increaseEmpSal", procedureName = "EMP_SAL_INCREMENT", resultClass=void.class, resultSetMapping = "", returnsResultSet = false, parameters = { @StoredProcedureParameter(name = "EMP_ID", queryParameter = "EMPID"), @StoredProcedureParameter(name = "SAL_INCR", queryParameter = "SALINCR")} ) Observe how Stored Procedure's arguments are handled easily in  @NamedStoredProcedureQuery using @StoredProcedureParameter.Expose Entity Bean by creating a Session Facade.Business method need to be added to Session Bean to access the Stored Procedure exposed as NamedQuery. public void salaryRaise(Long empId, Long salIncrease) throws Exception { try{ Query query = em.createNamedQuery("Employees.increaseEmpSal"); query.setParameter("EMPID", empId); query.setParameter("SALINCR", salIncrease); query.executeUpdate(); } catch(Exception ex){ throw ex; } } Expose business method through Session Bean Remote Interface. void salaryRaise(Long empId, Long salIncrease) throws Exception; Session Bean Client is required to invoke the method exposed through remote interface.Call exposed method in Session Bean Client main method. final Context context = getInitialContext(); SessionEJB sessionEJB = (SessionEJB)context.lookup("Your-JNDI-lookup"); sessionEJB.salaryRaise(new Long(200), new Long(1000)); Deploy Session BeanRun Session Bean Client.Salary of Employee with Id 200 will be increased by 1000.

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