The singleton is a design pattern to ensure that exactly one application-wide instance of a particular class exists.
-1
votes
0answers
12 views
Java Singleton design pattern [migrated]
Can someone explain how my Junit passed successfully with below singleton implementation
EagerInitializations.java (singleton)
...
1
vote
1answer
74 views
Throwing exception in the singleton pattern in C#
I'm implementing an HTTP client shell that's going to be used for the lifetime of my application in C#. It needs to be initialized before the instance can be accessed. It looks something like this:
...
1
vote
1answer
39 views
Singleton implementation of Cache Dependency Manager
I am trying to implement a singleton CacheDependencyManager, by combining this CacheDependencyManager from Steve Greatrex with a singleton pattern from Jon Skeet (example 6).
I'd really appreciate ...
1
vote
0answers
22 views
JavaScript sound manager (singleton / static object using observer pattern)
I have some JavaScript code i would like your feedback on please.
My goals:
SoundManager should be a singleton/static class that has one instance.
...
-1
votes
1answer
64 views
Singleton Service Initialization [closed]
Is it ok to have a Singleton Service with Initialization like this?
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1
vote
0answers
53 views
Claims authorization service usage
I'm doing an AuthorizationService. I'm not sure how to do the usage interface of this service, so that it's practical and handy. It doesn't necessarily has to be an ...
-2
votes
1answer
67 views
Enum Singleton implementation in Java
I just wanted to implement the enum singleton in java. Here is my implementation where I have tried to create a singleton DataSource instance:
...
0
votes
0answers
45 views
Ingest data from an RDBMS to Hadoop Hive database using Sqoop
Context: The below code will run a series of steps in an ETL workflow. I would like the code to be reviewed to avoid memory bottlenecks and null pointer exceptions etc.
UseCase:
Ingest the data from ...
6
votes
1answer
114 views
Generic singleton array with archiving and insertion functions
I find that I often have to maintain a singleton primarily to hold an array that is sometimes persisted between user sessions, that should have only one class of items, and that sometimes needs to be ...
2
votes
1answer
93 views
Singleton Class for WordPress Plugin
I'm developing a WordPress plugin using the singleton pattern with the following requirements:
There should ever exist one instance of the plugin
Another instance of the object should never be ...
5
votes
3answers
104 views
Loading Configurations from plist into singleton
In my iOS application, I've created a singleton class that reads a configuration plist file and provides accessor methods to easily retrieve the values:
...
3
votes
0answers
39 views
Threadsafe singleton factory to use in Apache thrift server RPC system
My goal was to write a factory that the code did not have to be edited. Thus I am registering my factory functions into a singleton factory. I am going to be using this code in Apache thrift server ...
1
vote
1answer
49 views
Application Configuration in PHP
I'm learning PHP and I know too many ways to configure the application.
I use this method:
Folder:
app
config
app.php
db.php
src
class.php
index.php
...
2
votes
1answer
90 views
(Y.E.S.E.J.) Yet Another Singleton with Enum in Java
I have a Java class which has to be generated only once for all the objects that I have - it is a small program. This singleton class holds a mapping of characters. I Googled stack overflow and found ...
6
votes
1answer
88 views
Android app with config and customization classes
I have an Android app with three different Activity classes. Each of the Activities uses and changes config and user-customization data stored in a wrapped ...
6
votes
2answers
160 views
Singleton-ish RMI Server
In this program there is a single remote server which performs miscellaneous work. Because there is only one server, it seems like a singleton pattern could fit well.
The problem that a distributed ...
6
votes
1answer
69 views
Creating an in-memory ViewCounter that commits to database every 10 minutes
This singleton is responsible for counting every pageview (called Routes in our case) we get by id, until the timer runs out and commits the results to the database in one query. Then the counter gets ...
2
votes
1answer
134 views
Global.asax singleton
Please help me decide whether this should be good or bad idea to declare a Singleton variable in Global.asax file. (It is not actually singleton pattern, I just want to make sure that only one ...
3
votes
1answer
186 views
Singleton base class
I just wrote a singleton base class for a hobby project I'm currently working on. Python is not my first language, which is why I am not sure if everything is done the pythonic way.
I also used ...
3
votes
2answers
277 views
Manage Sessions within a Singleton
I am looking for advice if the below code is a good idea or not. If not, why? I am building a website which allows a user to purchase items. The user account and cart items will be stored in Session. ...
2
votes
1answer
39 views
Javascript singleton to notify different objects of changes in viewport size
I'm working on a singleton object to manage size changes in the viewport, I wanted it to be a singleton because there may be different unrelated objects that need to be notified when a change in ...
2
votes
1answer
50 views
6
votes
2answers
206 views
Building in the built-in declarations
In order for Rubberduck to be able to "recognize" the built-in VBA functions, procedures and objects, I added yet another constructor parameter to my Declaration ...
1
vote
1answer
160 views
Dependency injection thread safety
Is it OK to mix different lifetime of ISerializer and ICacheProvider in this case? I am using Unity DI. In this case, whenever ...
0
votes
1answer
168 views
0
votes
1answer
1k views
A Singleton Base and derived class
I have a base and derived class since I need to have different kinds of concrete classes.
I cannot use the getInstance() function in the base class since I cannot ...
3
votes
1answer
136 views
Reducing lock contention for a caching utility, or make it totally lockless but threadsafe
My Java program is a module called configProxy which fetches configuration entries from a remote node (say from a Redis instance). When the caller calls the ...
31
votes
4answers
23k views
Swift 1.2 Singleton Implementation
I am pretty new to Swift, as a solo developer I was wondering if somebody could pass comments on the singleton implementation below. The code does work, but being new to Swift and knowing that there ...
4
votes
1answer
147 views
Correct usage for singleton and reusability?
I've made the following DataSetReader, DS Attribute, and DataSetManager.
My main concerns ...
5
votes
3answers
822 views
Design of a remoteControl class for connecting to electronic devices
In a course that I'm taking on learning object oriented programming in java, I have completed an assignment for modeling a home entertainment system and the ability for a user to be able to use a ...
0
votes
1answer
166 views
PHP framework building: initializer and object loader classes
I am building a PHP framework and would like to get some feedback on a few different sections of the project. I consider myself still a neophyte in PHP so I would like to ask if I'm going about ...
1
vote
1answer
46 views
Managing a collection of object instances and getting them back out with instance manager / service locator
I'm creating an event loop for an asynchronous event execution library for PHP in PHP. Note that this is for a library and not an application. My event loop is just that -- a simple event loop that ...
3
votes
1answer
98 views
Execute startup method asynchronously
The goal is to call startManager on application start so that the manager is initialized in background without blocking application main thread.
Is it a safe ...
12
votes
1answer
120 views
Storing messages for the application's runtime
I am currently writing a well.. manual testing site for a chat-based bot. The full code can be found on github.
For that purpose I had to keep track of the messages currently in the "system". The ...
3
votes
1answer
173 views
Blocking builder with singleton
I am trying to implement a singleton builder that would be shared across
multiple builder threads for Coordinate objects.
Here is the simplified target class ...
3
votes
1answer
251 views
Ensure only a single instance of static template class member
I am interacting with a C library, whose documentation states that certain functions are not thread safe. Since its functions deal heterogeneously with multiple types, I have written a template ...
1
vote
0answers
99 views
Singleton request validator and sanitizor class
I have tried to code a PHP singleton class for validating multiple/single fields (sanitizing is optional). When validating single field, on success it will return 1 (...
5
votes
2answers
673 views
Thread-safe Phoenix Singleton class template with Boost
I've implemented the phoenix-singleton as a class template with boost inspired by Modern C++ Design. The code compiles fine with MSVC 2013 - and it seems to work, but I'm new
to multi-threaded ...
8
votes
1answer
2k views
Can we now `implement Singleton` using Java 8?
After my success with extending enum - I thought I would try to make Singleton creation as simple as possible since Java-8 makes ...
1
vote
2answers
531 views
Proper way to wait end of a service and singleton design
My code works fine and I would like to know if I chose the best strategy to implement my code, or if It can written better (more fast, more clear, best use of design pattern, etc).
In my android ...
2
votes
1answer
190 views
Lazy singleton with BackboneJS
I am trying to have a Backbone.Model which is a singleton and I wish to instantiate it lazily. I only need to support modern browsers so please do not worry about the use of ES5 getter.
Is this the ...
10
votes
5answers
6k views
Singleton Database class
Currently my team is building an application involving a database. We have to write a lot of data (approx 2,000,000 records) to the database and therefore we decided to open a connection once and ...
8
votes
3answers
675 views
Singleton Database wrapper
Before everybody yells at me about why I wrote a PDO wrapper class, it's to avoid writing try/catch, ...
3
votes
2answers
1k views
Correct way to implement a Singleton field
I have a helper class that does HTTP operations on Android. Every method uses a client field. I think it's a good idea to make this client a singleton since every method in the class uses it.
The ...
4
votes
2answers
1k views
Singleton necessary in DAO
I am using a singleton in my DAO. Would I be better with static methods? Also, should I be worried about synchronization of the singleton and my data statures?
...
4
votes
2answers
162 views
Address book with singletons
My main goal with this refactor was to change instance methods that should have been class methods in the first place into class methods. My secondary goal was to add singletons to these classes ...
4
votes
2answers
81 views
Static variable representing program state accessed with multiple functions
I have this method that performs certain functions based on the state that the algorithm is currently at:
...
2
votes
2answers
1k views
PHP Trait Singleton
An implementation of the singleton pattern in PHP using a trait (added in 5.4). Is there anything missing, any ways to create a second copy of the class?
...
6
votes
1answer
1k views
Searching for songs on an Android application
In my application I need to search for some songs on my external storage card every now and then. On startup I read everything, however when it comes to new activities I thought I could just pass the ...
5
votes
2answers
667 views
Android global data
I have a huge list of song objects in my program and I need those objects in almost all activities. Well, at least a part of it up to everything.
So I created a class which looks pretty much like ...
