Search Results

Search found 30780 results on 1232 pages for 'object oriented modeling'.

Page 16/1232 | < Previous Page | 12 13 14 15 16 17 18 19 20 21 22 23  | Next Page >

  • Best way to model Customer <--> Address

    - by Jen
    Every Customer has a physical address and an optional mailing address. What is your preferred way to model this? Option 1. Customer has foreign key to Address Customer (id, phys_address_id, mail_address_id) Address (id, street, city, etc.) Option 2. Customer has one-to-many relationship to Address, which contains a field to describe the address type Customer (id) Address (id, customer_id, address_type, street, city, etc.) Option 3. Address information is de-normalized and stored in Customer Customer (id, phys_street, phys_city, etc. mail_street, mail_city, etc.) One of my overriding goals is to simplify the object-relational mappings, so I'm leaning towards the first approach. What are your thoughts?

    Read the article

  • Return an Object in Java

    - by digby12
    I've been struggling to work out how to return an object. I have the following array of objects. ArrayList<Object> favourites; I want to find an object in the array based on it's "description" property. public Item finditem(String description) { for (Object x : favourites) { if(description.equals(x.getDescription())) { return Object x; else { return null; Can someone please show me how I would write this code. Thanks.

    Read the article

  • Finding the normals of an oriented bounding box?

    - by Milo
    Here is my problem. I'm working on the physics for my 2D game. All objects are oriented bounding boxes (OBB) based on the separate axis theorem. In order to do collision resolution, I need to be able to get an object out out of the object it is penetrating. To do this I need to find the normal of the face(s) that the other OBB is touching. Example: The small red OBB is a car lets say, and the big OBB is a static building. I need to determine the unit vector that is the normal of the building edge(s) the car is penetrating to get the car out of there. Here are my questions: How do I determine which edges the car is penetrating. I know how to determine the normal of an edge, but how do I know if I need (-dy, dx) or (dy, -dx)? In the case I'm demonstrating the car is penetrating 2 edges, which edge(s) do I use to get it out? Answers or help with any or all of these is greatly appreciated. Thank you

    Read the article

  • How to use the unit of work and repository patterns in a service oriented enviroment

    - by A. Karimi
    I've created an application framework using the unit of work and repository patterns for it's data layer. Data consumer layers such as presentation depend on the data layer design. For example a CRUD abstract form has a dependency to a repository (IRepository). This architecture works like a charm in client/server environments (Ex. a WPF application and a SQL Server). But I'm looking for a good pattern to change or reuse this architecture for a service oriented environment. Of course I have some ideas: Idea 1: The "Adapter" design pattern Keep the current architecture and create a new unit of work and repository implementation which can work with a service instead of the ORM. Data layer consumers are loosely coupled to the data layer so it's possible but the problem is about the unit of work; I have to create a context which tracks the objects state at the client side and sends the changes to the server side on calling the "Commit" (Something that I think the RIA has done for Silverlight). Here the diagram: ----------- CLIENT----------- | ------------------ SERVER ---------------------- [ UI ] -> [ UoW/Repository ] ---> [ Web Services ] -> [ UoW/Repository ] -> [DB] Idea 2: Add another layer Add another layer (let say "local services" or "data provider"), then put it between the data layer (unit of work and repository) and the data consumer layers (like UI). Then I have to rewrite the consumer classes (CRUD and other classes which are dependent to IRepository) to depend on another interface. And the diagram: ----------------- CLIENT ------------------ | ------------------- SERVER --------------------- [ UI ] -> [ Local Services/Data Provider ] ---> [ Web Services ] -> [ UoW/Repository ] -> [DB] Please note that I have the local services layer on the current architecture but it doesn't expose the data layer functionality. In another word the UI layer can communicate with both of the data and local services layers whereas the local services layer also uses the data layer. | | | | | | | | ---> | Local Services | ---> | | | UI | | | | Data | | | | | | | ----------------------------> | |

    Read the article

  • Effective handling of variables in non-object oriented programming

    - by srnka
    What is the best method to use and share variables between functions in non object-oriented program languages? Let's say that I use 10 parameters from DB, ID and 9 other values linked to it. I need to work with all 10 parameters in many functions. I can do it next ways: 1. call functions only with using ID and in every function get the other parameters from DB. Advantage: local variables are clear visible, there is only one input parameter to function Disadvantage: it's slow and there are the same rows for getting parameters in every function, which makes function longer and not so clear 2. call functions with all 10 parameters Advantage: working with local variables, clear function code Disadvantage: many input parameters, what is not nice 3. getting parameters as global variables once and using them everywhere Advantage - clearer code, shorter functions, faster processing Disadvantage - global variables - loosing control of them, possibility of unwanted overwriting (Especially when some functions should change their values) Maybe there is some another way how to implement this and make program cleaner and more effective. Can you say which way is the best for solving this issue?

    Read the article

  • Impact of Service Oriented Architecture (SOA) on Business and IT Operations

    The impact of Service Oriented Architecture (SOA) on business and IT operations varies from company to company. I think more and more companies are starting to view SOA as just another technology that they can incorporate in an existing or new system. One of the driving factors in using SOA is the reduction in maintenance costs and decrease in the time needed to bring products to market. The reductions in costs, and reduced turnaround time can be directly converted in to increased profitability due to less expenditures that are needed in order to maintain or create new systems. My personal perspective on SOA is that it is great for what it is actually intended to do. SOA allows systems to be distributed across networks or even the world while ensuring enterprise processing consistency, data integrity and preventing code duplication. This being said a lot of preparation and work goes into properly designing and implementing an SOA especially if an enterprise wants to take full advantage of its benefits. Even though SOA has recently gotten a lot of hype about its benefits it does not a perfect fit for all situations. At the end of the day SOA is just another tool in my tool belt that I can pull from to create solutions that meet the business’s needs. Based on current industry trends SOA appears to be a very solid technology to use moving forward, especially as more and more companies shift towards cloud based computing. It is important to remember that SOA is one of many technologies that can be used in creating business solutions and I think more time will be spent in the future evaluating if SOA is the right technology for a solution once the initial hype of SOA has calmed down.

    Read the article

  • Trouble accessing fields of a serialized object in Java

    - by typoknig
    I have instantized a class that implements Serializable and I am trying to stream that object like this: try{ Socket socket = new Socket("localhost", 8000); ObjectOutputStream toServer = new ObjectOutputStream(socket.getOutputStream()); toServer.writeObject(myObject); } catch (IOException ex) { System.err.println(ex); } All good so far right? Then I am trying to read the fields of that object like this: //This is an inner class class HandleClient implements Runnable{ private ObjectInputStream fromClient; private Socket socket; // This socket was established earlier try { fromClient = new ObjectInputStream(socket.getInputStream()); GetField inputObjectFields = fromClient.readFields(); double myFristVariable = inputObjectFields.get("myFirstVariable", 0); int mySecondVariable = inputObjectFields.get("mySecondVariable", 0); //do stuff } catch (IOException ex) { System.err.println(ex); } catch (ClassNotFoundException ex) { System.err.println(ex); } finally { try { fromClient.close(); } catch (Exception ex) { ex.printStackTrace(); } } } But I always get the error: java.io.NotActiveException: not in call to readObject This is my first time streaming objects instead of primitive data types, what am I doing wrong? BONUS When I do get this working correctly, is the ENTIRE CLASS passed with the serialized object (i.e. will I have access to the methods of the object's class)? My reading suggests that the entire class is passed with the object, but I have been unable to use the objects methods thus far. How exactly do I call on the object's methods? In addition to my code above I also experimented with the readObject method, but I was probably using it wrong too because I couldn't get it to work. Please enlighten me.

    Read the article

  • Why does C++ behave this way?

    - by eSKay
    #include<stdio.h> int b = 0; class A { public: int a;}; class B: public A { int c; int d; public: B(){ b++; a = b; printf("B:%d\n",b); } }; int main() { A* a = new B[10]; B* b = new B[10]; printf("\n%d", a->a); a++; printf("\n%d", a->a); // prints junk value printf("\n\n%d", b->a); b++; printf("\n%d", b->a); return 0; } The second printf prints a junk value. It should figure that it is pointing to an object of type B and increment by the sizof(B). Why does that not happen?

    Read the article

  • Blob object not working properly even though the class is seralized

    - by GustlyWind
    I have class which is seralized and does convert a very large amount of data object to blob to save it to database.In the same class there is decode method to convert blob to the actual object.Following is the code for encode and decode of the object. private byte[] encode(ScheduledReport schedSTDReport) { byte[] bytes = null; try { ByteArrayOutputStream bos = new ByteArrayOutputStream(); ObjectOutputStream oos = new ObjectOutputStream(bos); oos.writeObject(schedSTDReport); oos.flush(); oos.close(); bos.close(); //byte [] data = bos.toByteArray(); //ByteArrayOutputStream baos = new ByteArrayOutputStream(); //GZIPOutputStream out = new GZIPOutputStream(baos); //XMLEncoder encoder = new XMLEncoder(out); //encoder.writeObject(schedSTDReport); //encoder.close(); bytes = bos.toByteArray(); //GZIPOutputStream out = new GZIPOutputStream(bos); //out.write(bytes); //bytes = bos.toByteArray(); } catch (Exception e) { _log.error("Exception caught while encoding/zipping Scheduled STDReport", e); } decode(bytes); return bytes; } /* * Decode the report definition blob back to the * ScheduledReport object. */ private ScheduledReport decode(byte[] bytes) { ByteArrayInputStream bais = new ByteArrayInputStream(bytes); ScheduledReport sSTDR = null; try { ObjectInputStream ois = new ObjectInputStream(bais); //GZIPInputStream in = new GZIPInputStream(bais); //XMLDecoder decoder = new XMLDecoder(in); sSTDR = (ScheduledReport)ois.readObject();//decoder.readObject(); //decoder.close(); } catch (Exception e) { _log.error("IOException caught while decoding/unzipping Scheduled STDReport", e); } return sSTDR; } The problem here is whenver I change something else in this class means any other method,a new class version is created and so the new version the class is unable to decode the originally encoded blob object. The object which I am passing for encode is also seralized object but this problem exists. Any ideas thanks

    Read the article

  • Push-Based Events in a Services Oriented Architecture

    - by Colin Morelli
    I have come to a point, in building a services oriented architecture (on top of Thrift), that I need to expose events and allow listeners. My initial thought was, "create an EventService" to handle publishing and subscribing to events. That EventService can use whatever implementation it desires to actually distribute the events. My client automatically round-robins service requests to available service hosts which are determined using Zookeeper-based service discovery. So, I'd probably use JMS inside of EventService mainly for the purpose of persisting messages (in the event that a service host for EventService goes down before it can distribute the message to all of the available listeners). When I started considering this, I began looking into the differences between Queues and Topics. Topics unfortunately won't work for me, because (at least for now), all listeners must receive the message (even if they were down at the time the event was pushed, or hadn't made a subscription yet because they haven't completed startup (during deployment, for example) - messages should be queued until the service is available). However, I don't want EventService to be responsible for handling all of the events. I don't think it should have the code to react to events inside of it. Each of the services should do what it needs with a given event. This would indicate that each service would need a JMS connection, which questions the value of having EventService at all (as the services could individually publish and subscribe to JMS directly). However, it also couples all of the services to JMS (when I'd rather that there be a single service that's responsible for determining how to distribute events). What I had thought was to publish an event to EventService, which pulls a configuration of listeners from some configuration source (database, flat file, irrelevant for now). It replicates the message and pushes each one back into a queue with information specific to that listener (so, if there are 3 listeners, 1 event would become 3 events in JMS). Then, another thread in EventService (which is replicated, running on multiple hots) would be pulling from the queue, attempting to make the service call to the "listener", and returning the message to the queue (if the service is down), or discarding the message (if the listener completed successfully). tl;dr If I have an EventService that is responsible for receiving events and delegating service calls to "event listeners," (which are really just endpoints on other services), how should it know how to craft the service call? Should I create a generic "Event" object that is shared among all services? Then, the EventService can just construct this object and pass it to the service call. Or is there a better answer to this problem entirely?

    Read the article

  • Encapsulate update method inside of object or have method which accepts an object to update

    - by Tom
    Hi, I actually have 2 questions related to each other: I have an object (class) called, say MyClass which holds data from my database. Currently I have a list of these objects ( List < MyClass ) that resides in a singleton in a "communal area". I feel it's easier to manage the data this way and I fail to see how passing a class around from object to object is beneficial over a singleton (I would be happy if someone can tell me why). Anyway, the data may change in the database from outside my program and so I have to update the data every so often. To update the list of the MyClass I have a method called say, Update, written in another class which accepts a list of MyClass. This updates all the instances of MyClass in the list. However would it be better instead to encapulate the Update() method inside the MyClass object, so instead I would say foreach(MyClass obj in MyClassList) { obj.update(); } What is a better implementation and why? The update method requires a XML reader. I have written an XML reader class which is basically a wrapper over the standard XML reader the language natively provides which provides application specific data collection. Should the XML reader class be in anyway in the "inheritance path" of the MyClass object - the MyClass objects inherits from the XML reader because it uses a few methods. I can't see why it should. I don't like the idea of declaring an instance of the XML Reader class inside of MyClass and an MyClass object is meant to be a simple "record" from the database and I feel giving it loads of methods, other object instances is a bit messy. Perhaps my XML reader class should be static but C#'s native XMLReader isn't static.? Any comments would be greatly appreciated Thanks Thomas

    Read the article

  • Object Design catalog and resources

    - by Tauren
    I'm looking for web sites, books, or other resources that provide a catalog of object designs used in common scenarios. I'm not looking for generic design patterns, but for samples of actual object designs that were used to solve real problems. For instance, I'm about to build an internal messaging system for a web application, similar to Facebook's messaging system. This system will allow administrators to send messages to all members, to selected groups of members, or to individuals. Members can send messages to other members or groups of members. Fairly common stuff and a feature that I'm sure thousands of web applications require. I know each situation is different and there are a million ways to design this solution. Although this scenario isn't really all that complex, I'm sure the basic design of the necessary objects and relationships for a system like this has already been done many times. It would be nice to review other similar designs before building my own. Is there a place where people can share their designs and others can browse/search through the catalog to review and provide feedback on them? StackOverflow could be used to a degree for this, but doesn't really provide a catalog of designs. Any other resources that would relate?

    Read the article

  • Using Zope object unique id ( _p_oid ) to access object itself

    - by Alex M
    Every Zope object has it's own unique id ( _p_oid ). To convert it into integer value: from Shared.DC.xml.ppml import u64 as decodeObjectId oid = decodeObjectId(getattr(<Object instance>, '_p_oid')) Is it possible to get object itself having it's _p_oid? I tried this: from ZODB.utils import p64 object = <RootObject instance>._p_jar[p64(oid)] But it seems it's a wrong way

    Read the article

  • Object database for website

    - by Damian
    I was planning to use db4o for a website. It's a microblog site with small posts and comments developed in java. The thing is I contacted db4o support asking if db4o would be suitable for a website, and they answered me that only for websites with low concurrency. That means with few requests? So, now I think db4o will not be a good choice. Do you know if there is any object database for java suitable for a website?

    Read the article

  • Difference in Django object creation call

    - by PhilGo20
    I'd like to know if there's a difference between the following two calls to create an object in Django Animal.objects.create(name="cat", sound="meow") and Animal(name="cat", sound="meow") I see both in test cases and I want to make sure I am not missing something. thanks

    Read the article

  • What is the use of Association, Aggregation and Composition (Encapsulation) in Classes

    - by SahilMahajanMj
    I have gone through lots of theories about what is encapsulation and the three techniques of implementing it, which are Association, Aggregation and Composition. What i found is, Encapsulation Encapsulation is the technique of making the fields in a class private and providing access to the fields via public methods. If a field is declared private, it cannot be accessed by anyone outside the class, thereby hiding the fields within the class. For this reason, encapsulation is also referred to as data hiding. Encapsulation can be described as a protective barrier that prevents the code and data being randomly accessed by other code defined outside the class. Access to the data and code is tightly controlled by an interface. The main benefit of encapsulation is the ability to modify our implemented code without breaking the code of others who use our code. With this feature Encapsulation gives maintainability, flexibility and extensibility to our code. Association Association is a relationship where all object have their own lifecycle and there is no owner. Let’s take an example of Teacher and Student. Multiple students can associate with single teacher and single student can associate with multiple teachers but there is no ownership between the objects and both have their own lifecycle. Both can create and delete independently. Aggregation Aggregation is a specialize form of Association where all object have their own lifecycle but there is ownership and child object can not belongs to another parent object. Let’s take an example of Department and teacher. A single teacher can not belongs to multiple departments, but if we delete the department teacher object will not destroy. We can think about “has-a” relationship. Composition Composition is again specialize form of Aggregation and we can call this as a “death” relationship. It is a strong type of Aggregation. Child object dose not have their lifecycle and if parent object deletes all child object will also be deleted. Let’s take again an example of relationship between House and rooms. House can contain multiple rooms there is no independent life of room and any room can not belongs to two different house if we delete the house room will automatically delete. The question is: Now these all are real world examples. I am looking for some description about how to use these techniques in actual class code. I mean what is the point for using three different techniques for encapsulation, How these techniques could be implemented and How to choose which technique is applicable at time.

    Read the article

  • Validation and Error Generation when using the Data Mapper Pattern

    - by AndyPerlitch
    I am working on saving state of an object to a database using the data mapper pattern, but I am looking for suggestions/guidance on the validation and error message generation step (step 4 below). Here are the general steps as I see them for doing this: (1) The data mapper is used to get current info (assoc array) about the object in db: +=====================================================+ | person_id | name | favorite_color | age | +=====================================================+ | 1 | Andy | Green | 24 | +-----------------------------------------------------+ mapper returns associative array, eg. Person_Mapper::getPersonById($id) : $person_row = array( 'person_id' => 1, 'name' => 'Andy', 'favorite_color' => 'Green', 'age' => '24', ); (2) the Person object constructor takes this array as an argument, populating its fields. class Person { protected $person_id; protected $name; protected $favorite_color; protected $age; function __construct(array $person_row) { $this->person_id = $person_row['person_id']; $this->name = $person_row['name']; $this->favorite_color = $person_row['favorite_color']; $this->age = $person_row['age']; } // getters and setters... public function toArray() { return array( 'person_id' => $this->person_id, 'name' => $this->name, 'favorite_color' => $this->favorite_color, 'age' => $this->age, ); } } (3a) (GET request) Inputs of an HTML form that is used to change info about the person is populated using Person::getters <form> <input type="text" name="name" value="<?=$person->getName()?>" /> <input type="text" name="favorite_color" value="<?=$person->getFavColor()?>" /> <input type="text" name="age" value="<?=$person->getAge()?>" /> </form> (3b) (POST request) Person object is altered with the POST data using Person::setters $person->setName($_POST['name']); $person->setFavColor($_POST['favorite_color']); $person->setAge($_POST['age']); *(4) Validation and error message generation on a per-field basis - Should this take place in the person object or the person mapper object? - Should data be validated BEFORE being placed into fields of the person object? (5) Data mapper saves the person object (updates row in the database): $person_mapper->savePerson($person); // the savePerson method uses $person->toArray() // to get data in a more digestible format for the // db gateway used by person_mapper Any guidance, suggestions, criticism, or name-calling would be greatly appreciated.

    Read the article

  • Consumer Oriented Search In Oracle Endeca Information Discovery – Part 1

    - by Bob Zurek
    Information Discovery, a core capability of Oracle Endeca Information Discovery, enables business users to rapidly search, discover and navigate through a wide variety of big data including structured, unstructured and semi-structured data. One of the key capabilities, among many, that differentiate our solution from others in the Information Discovery market is our deep support for search across this growing amount of varied big data. Our method and approach is very different than classic simple keyword search that is found in may information discovery solutions. In this first part of a series on the topic of search, I will walk you through many of the key capabilities that go beyond the simple search box that you might experience in products where search was clearly an afterthought or attempt to catch up to our core capabilities in this area. Lets explore. The core data management solution of Oracle Endeca Information Discovery is the Endeca Server, a hybrid search-analytical database that his highly scalable and column-oriented in nature. We will talk in more technical detail about the capabilities of the Endeca Server in future blog posts as this post is intended to give you a feel for the deep search capabilities that are an integral part of the Endeca Server. The Endeca Server provides best-of-breed search features aw well as a new class of features that are the first to be designed around the requirement to bridge structured, semi-structured and unstructured big data. Some of the key features of search include type a heads, automatic alphanumeric spell corrections, positional search, Booleans, wildcarding, natural language, and category search and query classification dialogs. This is just a subset of the advanced search capabilities found in Oracle Endeca Information Discovery. Search is an important feature that makes it possible for business users to explore on the diverse data sets the Endeca Server can hold at any one time. The search capabilities in the Endeca server differ from other Information Discovery products with simple “search boxes” in the following ways: The Endeca Server Supports Exploratory Search.  Enterprise data frequently requires the user to explore content through an ad hoc dialog, with guidance that helps them succeed. This has implications for how to design search features. Traditional search doesn’t assume a dialog, and so it uses relevance ranking to get its best guess to the top of the results list. It calculates many relevance factors for each query, like word frequency, distance, and meaning, and then reduces those many factors to a single score based on a proprietary “black box” formula. But how can a business users, searching, act on the information that the document is say only 38.1% relevant? In contrast, exploratory search gives users the opportunity to clarify what is relevant to them through refinements and summaries. This approach has received consumer endorsement through popular ecommerce sites where guided navigation across a broad range of products has helped consumers better discover choices that meet their, sometimes undetermined requirements. This same model exists in Oracle Endeca Information Discovery. In fact, the Endeca Server powers many of the most popular e-commerce sites in the world. The Endeca Server Supports Cascading Relevance. Traditional approaches of search reduce many relevance weights to a single score. This means that if a result with a good title match gets a similar score to one with an exact phrase match, they’ll appear next to each other in a list. But a user can’t deduce from their score why each got it’s ranking, even though that information could be valuable. Oracle Endeca Information Discovery takes a different approach. The Endeca Server stratifies results by a primary relevance strategy, and then breaks ties within a strata by ordering them with a secondary strategy, and so on. Application managers get the explicit means to compose these strategies based on their knowledge of their own domain. This approach gives both business users and managers a deterministic way to set and understand relevance. Now that you have an understanding of two of the core search capabilities in Oracle Endeca Information Discovery, our next blog post on this topic will discuss more advanced features including set search, second-order relevance as well as an understanding of faceted search mechanisms that include queries and filters.  

    Read the article

  • Open Source .Net Object Database or Document Database for use in Hosted environment

    - by runxc1 Bret Ferrier
    I am looking at creating a web site and I want to try and learn either a Object Database or a Document Database. I am going to be using a hosting provider so I won't be able to install any software. I am unable to purchase any licensing so I need to be able use either a free or open source Object/Document Database. Are there any free Object/Document Databases that don't require installation of some sort?

    Read the article

  • Passing object from PHP to Mysql Stored procedure

    - by user268982
    Hi All, Scenario :- I have to call MYSQL stored procedure from PHP and do some operations ( around 15 commands ) on the database Problem :- I have to call stored procedure with 36 parameters. Lot of parameters . I don't think it is a good idea to pass these many individual parameters and even heard passing individul parameters increases network traffic. Looking for :- I created a Data Object at PHP side and is there any way I can create similar kind of Object in MYSQL and pass this object as a parameter and extract the data from the object in MYSQL stored procedure Thanks for your help Regards Kiran

    Read the article

  • Explore a COM Object in PHP

    - by shaiss
    What would be the proper way to explode a COM object for debugging? I have a 3rd party function that returns a multilevel object. The documentation is non existant, so I'd like to be able to echo everything out of the object or debug it in Komodo IDE. Komodo just says Object and nothing else. Maybe convert to array? I know some of the existing options such as $com->Status, but there are more variables returned that I'd like to know what they are.

    Read the article

  • Proper way to set object instance variables

    - by ensnare
    I'm writing a class to insert users into a database, and before I get too far in, I just want to make sure that my OO approach is clean: class User(object): def setName(self,name): #Do sanity checks on name self._name = name def setPassword(self,password): #Check password length > 6 characters #Encrypt to md5 self._password = password def commit(self): #Commit to database >>u = User() >>u.setName('Jason Martinez') >>u.setPassword('linebreak') >>u.commit() Is this the right approach? Should I declare class variables up top? Should I use a _ in front of all the class variables to make them private? Thanks for helping out.

    Read the article

< Previous Page | 12 13 14 15 16 17 18 19 20 21 22 23  | Next Page >