I would like to do something like this: public class Foo { // Probably really a Guid, but I'm using a string here for simplicity's sake. string Id { get; set; } int Data { get; set; } public Foo (int data) { ... } ... } public static class FooManager { Dictionary<string, Foo> foos = new Dictionary...
I am making a program which makes use of a couple of constants. At first, each time I needed to use a constant, I'd define it as //C# private static readonly int MyConstant = xxx; //Java private static final int MyConstant = xxx; in the class where I'd need it. After some time, I started to realise that some constants would be needed...
Hi, I created a Singleton class in c#, with a public property that I want to initialize when the Singleton is first called. This is the code I wrote : public class BL { private ISessionFactory _sessionFactory; public ISessionFactory SessionFactory { get { return _sessionFactory; } set { _sessionFactory = va...
I want to create a set of classes that share a lot of common behavior. Of course in OOP when you think that you automatically think "abstract class with subclasses". But among the things I want these classes to do is to each have a static list of instances of the class. The list should function as sort of a singleton within the class. I ...
I'm trying to implement a Singleton in Tomcat 6.24 on Linux with x86_64 OpenJDK 1.6. My application is just a bunch of JSPs and some static content and the JSPs make calls to my Java code. Currently the web.xml just looks like this: <web-app xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-insta...
Does it matter if the constructor/destructor implementation is provided in the header file or the source file? For example, which way is preferred and why? Way 1: class Singleton { public: ~Singleton() { } private: Singleton() { } }; Way 2: class Singleton { public: ~Singleton(); private: Singleton(); }; ...
Hi Friends, I have developed a small iPhone application by using singleton that I use to navigate through the views. Here is a sample method from my singleton class. + (void) loadMenuController:(NSMutableArray *)menuItems{ MenuViewController *menuViewControler = [[MenuViewController alloc] initWithNibName:@"MenuViewController" bun...
Hello Everyone There are already quite some posts about the Singleton-Pattern around, but I would like to start another one on this topic since I would like to know if the Factory-Pattern would be the right approach to remove this "anti-pattern". In the past I used the singleton quite a lot, also did my fellow collegues since it is so ...
Hey, Don't find any good answer to this simple question about helper/utils classes: Why would i create a singleton (stateless) rather than static methods? Why an object instance could be needed while the object has no state? Sometimes i really don't know what to use... ...
Hi All I have a J2SE application having user threads running in a separate JVM outside JBOSS server. During startup, J2SE invokes a EJB inside jboss, by passing a new object(singleton) of simple JAVA VO class having getter/setter methods. {The VO class is a singleton and implements serialiable(as mandated by EJB)}. EJB receives the ob...
A day ago my application was one EAR, containing one WAR, one EJB JAR, and a couple of utility JAR files. I had a POJO singleton class in one of those utility files, it worked, and all was well with the world: EAR |--- WAR |--- EJB JAR |--- Util 1 JAR |--- Util 2 JAR |--- etc. Then I created a second WAR and found out (the hard w...
Today I faced one question in interview. Is it possible to apply inheritance concept on Singleton Classes? I said since the constructor is private, we cannot extend that Singleton class. Next thing he asked me is to apply inheritance on that Singleton class. So, I made the Singleton's constructor as protected thinking that child's const...
Hi all, I want to implement the concept of a Workspace. This is a global concept - all other code will interact with one instance of this Workspace. The Workspace will be responsible for maintaining the current system state (i.e. interacting with the system model, persisting the system state etc) So what's the best design strategy for...
I am working on a simple abstract database class. In my usage of this class, I'll want to have some instance be a singleton. I was thinking of having a abstract class that is not a singleton, and then extend it into another abstract class that is a singleton. Is this possible? Recommended? Edit: I want to have two abstract that are p...
I decided to use the singleton design pattern while creating a view helper class. This got me thinking; will the singleton instance survive across requests? This led to another question, Which variables (if any) survive across web requests and does that change depending on deployment? (Fastcgi, Mongrel, Passenger, ...) I know that Con...
i have this code: class IC_Core { /** * Database * @var IC_Database */ public static $db = NULL; /** * Core * @var IC_Core */ protected static $_instance = NULL; private function __construct() { } public static function getInstance() { if ( ! is_object(self::$_instan...
Below code instantiates a derived singleton object based on environment variable. The compiler errors saying error C2512: 'Dotted' : no appropriate default constructor. I don't understand what the compiler is complaining about. EDIT: Fixed issues with implementing the get instance method which requires definition of both the parent and ...
The Repository class has singleton behavior and the _db implements the disposable pattern. As excepted the _db object gets disposed after the first call and because of the singleton behavior any other call of _db will crash. [ServiceBehavior(InstanceContextMode=InstanceContextMode.Single)] public class Repository : IRepository { ...
I am currently trying to create a test suite for my javascript apps. My problem is that, it seems I cannot get access to init() from my utils object, as you can see below: I have my app that follow a singleton pattern: var appModal = function () { var utils = Object.create(moduleUtils); function init(caller, options ) { } ...
Here's my singleton code (pretty much boilerplate): @interface DataManager : NSObject { NSMutableArray *eventList; } @property (nonatomic, retain) NSMutableArray *eventList; +(DataManager*)sharedDataManager; @end And then the .m: #import "DataManager.h" static DataManager *singletonDataManager = nil; @implementation DataMana...