What is purpose of Service Locator?
The purpose of the Service Locator pattern is to return the service instances on demand. This is useful for decoupling service consumers from concrete classes. An implementation will consist of the following components: Client – the client object is a service consumer.
When to use Service Locator pattern?
The service locator design pattern is used when we want to locate various services using JNDI lookup. Considering high cost of looking up JNDI for a service, Service Locator pattern makes use of caching technique. For the first time a service is required, Service Locator looks up in JNDI and caches the service object.
What is the use of Service Locator in C#?
The Service Locator is a pattern by which we can reduce the dependency of one object on another that we will see shortly and Dependency injection (DI) is another smart solution for the same problem.
What is Java Service Locator?
The Service Locator abstracts the API lookup (naming) services, vendor dependencies, lookup complexities, and business object creation, and provides a simple interface to clients. This reduces the client’s complexity. In addition, the same client or other clients can reuse the Service Locator.
What is the dependency injection?
In object-oriented programming (OOP) software design, dependency injection (DI) is the process of supplying a resource that a given piece of code requires. The required resource, which is often a component of the application itself, is called a dependency.
Is service locator an anti pattern?
Service Locator is a dangerous pattern because it almost works. You can locate Dependencies from consuming classes, and you can replace those Dependencies with different implementations — even with Test Doubles from unit tests.
What is provider pattern in Java?
Provider pattern allows the developers to create pluggable components. It was first introduced in framework 2.0 and it has lot of features like “Membership Provider”, “Roles Provider” etc. and instantiates using configuration file.
What is Dao file in Java?
The Data Access Object (or DAO) pattern: separates a data resource’s client interface from its data access mechanisms. adapts a specific data resource’s access API to a generic client interface.
What is difference between IoC and DI in Spring?
Spring IoC (Inversion of Control) Container is the core of Spring Framework. It creates the objects, configures and assembles their dependencies, manages their entire life cycle. The Container uses Dependency Injection(DI) to manage the components that make up the application.
What is the scope of Bean in portlet context?
global-session
global-session is scope of bean in portlet context.
What are providers software?
Provider Software means software which is proprietary to the Provider, including software which is or will be used by the Provider for the purposes of providing the Services.
What are provider classes?
The Provider class is the interface to such a package or set of packages. It has methods for accessing the provider name, version number, and other information.
How to get an instance of a class from a service locator?
You could call ServiceLocator::GetComponent (type, contract) to get an object and somehow the service locator would return an instance of the class you requested. Similar to the COM implementation, the Service locator should use a factory in the background to create the instance of the class.
What is a service locator in Java?
A Service Locator is a common design pattern that allows decoupling clients of services (described by a public interface) from the concrete class implementing those services. Martin Fowler has a great introduction on the topic in his Inversion of Control Containers and the Dependency Injection pattern.
How does the service locator activate the services?
The locator does not activate the services itself but uses activators to do so. This decouples the locator from various ways to create instances of services e.g., create an instance of a service from a local assembly or connect to a remote service using remoting or WCF.
What is the difference between service locator and di?
The primary difference being that if you use service locator pattern, your classes are explicitly dependent on service locator while DI performs auto-wiring to keep your individual classes independent of service locator (classes are ‘given/injected with’ dependencies by an ‘assembler’). An DI can also act as a locator in some aspects.