dependency-injection

问题 I've had a certain feeling these last couple of days that dependency-injection should really be called "I can't make up my mind"-pattern. I know this might sound silly, but really it's about the reasoning behind why I should use Dependency Injection (DI). Often it is said that I should use DI, to achieve a higher level of loose-coupling, and I get that part. But really... how often do I change my database, once my choice has fallen on MS SQL or MySQL .. Very rarely right? Does anyone have

问题 I've had a certain feeling these last couple of days that dependency-injection should really be called "I can't make up my mind"-pattern. I know this might sound silly, but really it's about the reasoning behind why I should use Dependency Injection (DI). Often it is said that I should use DI, to achieve a higher level of loose-coupling, and I get that part. But really... how often do I change my database, once my choice has fallen on MS SQL or MySQL .. Very rarely right? Does anyone have

问题 I am migrating an application to Java EE 7 and would like to CDI 1.1. But I don't get the meaning of bean-discovery-mode="annotated" . The CDI 1.1 specification is not very helpful. At least I have not found any useful paragraph. Did I miss it? This example runs perfectly with bean-discovery-mode="all" and injects an instance of LoggingClass : public class LoggingClass { public Logger logger = Logger.getLogger("ALOGGER"); } @Test public class MMLoggerProducerIT extends Arquillian { @Inject

问题 So I have seen this question: Spring dependency injection to other instance and was wondering if my method will work out. 1) Declare beans in my Spring application context <bean id="dataSource" destroy-method="close" class="org.apache.commons.dbcp.BasicDataSource"> <property name="driverClassName" value="${jdbc.driverClassName}"/> <property name="url" value="${jdbc.url}" /> <property name="username" value="${jdbc.username}" /> <property name="password" value="${jdbc.password}" /> <property

问题 I am totally confused about inject in Angular. I do not know where to use it and why. Is it only used with factory as described here? myController.$inject = ['$scope','notify']; Here notify is the name of the factory. 回答1: That is one approach to support Dependency Injection after your code is minified (if you choose to minify). When you declare a controller, the function takes parameters: function ($scope, notify) When you minify the code, your function will look like this: function (a, b)

问题 My understanding: A dependency is when an instance of ClassA requires an instance of ClassB to instantiate a new instance of ClassA. A dependency injection is when ClassA is passed an instance of ClassB, either through a parameter in ClassA's constructor or through a set~DependencyNameHere~(~DependencyNameHere~ $param) function. (This is one of the areas I'm not completely certain on) . An IoC container is a singleton Class(can only have 1 instance instantiated at any given time) where the

问题 I currently creating some experimental projects with nodejs. I have programmed a lot Java EE web applications with Spring and appreciated the ease of dependency injection there. Now I am curious: How do I do dependency injection with node? Or: Do I even need it? Is there a replacing concept, because the programming style is different? I am talking about simple things, like sharing a database connection object, so far, but I have not found a solution that satisfies me. 回答1: In short, you don't

问题 Recently I've come accross a problem where I have to select a type based on a parameter. For example: a class used for sending notifications that should select the right channel (email, sms, ...) based on an input-parameter. I looks something like this: public class NotificationManager { IEmail _email; ISms _sms; public NotificationManager (IEmail email, ISMS sms) { _email = email; _sms = sms; } public void Send(string type) { switch(type) { case "email": _email.send; break; case "sms": _sms

问题 Can someone explain dependency injection with a basic .NET example and provide a few links to .NET resources to extend on the subject? This is not a duplicate of What is dependency injection? because I am asking about specific .NET examples and resources. 回答1: Here's a common example. You need to log in your application. But, at design time, you're not sure if the client wants to log to a database, files, or the event log. So, you want to use DI to defer that choice to one that can be

问题 Can someone explain dependency injection with a basic .NET example and provide a few links to .NET resources to extend on the subject? This is not a duplicate of What is dependency injection? because I am asking about specific .NET examples and resources. 回答1: Here's a common example. You need to log in your application. But, at design time, you're not sure if the client wants to log to a database, files, or the event log. So, you want to use DI to defer that choice to one that can be