Use Picocontainer Core to achieve the best practical guide to inject

Use Picocontainer Core to achieve the best practical guide to inject introduce Dependency inject is a design mode commonly used in application development that can reduce the coupling of code and improve testability.Picocontainer Core is a lightweight Java dependent injection container, which can help us achieve dependency injection.This article will introduce how to use Picocontainer Core to achieve the best practice that depends on injection. Install First, we need to add Picocontainer Core to our project.You can complete the installation by adding the following dependencies to the construction file (such as maven's pom.xml) to complete the installation: <dependency> <groupId>org.picocontainer</groupId> <artifactId>picocontainer</artifactId> <version>2.15</version> </dependency> Basic usage Next, we will introduce the basic usage of Picocontainer Core. 1. Definition dependency item First, we need to define our dependence items.Suppose we have a class called UserService, which depends on an interface named UserRepository.We can define the dependencies through the following ways: public interface UserRepository { // Method definition } public class UserService { private final UserRepository userRepository; public UserService(UserRepository userRepository) { this.userRepository = userRepository; } // Other methods } 2. Create a container Next, we need to create a Picocontainer container and register the dependency item into the container.You can create a container through the following ways: import org.picocontainer.DefaultPicoContainer; import org.picocontainer.MutablePicoContainer; MutablePicoContainer container = new DefaultPicoContainer(); container.addComponent(UserRepository.class, UserRepositoryImpl.class); In this way, a Picocontainer container is created and the UserRePOSITOMPL class is injected into the UserRePOSITORY interface. 3. Analysis dependency item Now, we can use a container to parse our dependence items.You can analyze the dependencies through the following ways: UserService userService = (UserService) container.getComponent(UserService.class); In this example, we have obtained an instance of UserService and automatically analyzed the UserRepository it dependent. 4. Use dependencies Now, we can use dependency items for programming.For example, we can use userService in the following ways: User user = userService.getUserById(1); In this example, we call UserService's GetUserbyID method, which may call UserRePOSITORY to get the specified ID users. Summarize By using Picocontainer Core, we can easily achieve dependency injection and make the code more modular and tested.In this article, we introduced the basic usage of Picocontainer Core and provided some example code to help readers better understand.It is hoped that this article can help readers understand how to use Picocontainer Core to achieve the best practice that depends on injection. Extra precautions -In when using Picocontainer Core, you can use custom container configuration to make more advanced configuration and customization. -When multiple implementation classes exist, you can use the naming strategy of Picocontainer Core to solve the problem of the dependencies. -PicoContainer Core also supports cycle -dependent solutions, but you need to use it carefully to avoid problems such as dead locks.