"Annotations for DS" framework technology in the Java class library

"Annotations for DS" framework technical principle in the Java class library "Annotations for DS" is a framework used in the Java class library to simplify and enhance the development process of using dependent injection and declaration service registration.This article will introduce the technical principles of the framework, and explain the complete programming code and related configuration when necessary. 1. What is dependency injection and declaration service registration? Dependent injection is a design model that is used to pull the dependent relationship required by the object from the code of the creation object, so that these dependencies can be injected into the object.Declaration service registration is a way to separate the service registration from the code, so that developers can register and manage the service through annotations or configuration files. 2. The basic principle of the "Annotations for DS" framework: a. Annotation mark: The framework is a class with a dependent injection or declaration of service registration through a custom annotation, such as@Component,@Service, etc. b. Annotation processor: The framework defines the annotation processor for scanning the annotations in the application during compilation or runtime, and generate the necessary code or configuration. c. Configuration file: The framework usually requires developers to provide a configuration file, which contains detailed information to the service to be registered, such as component names, dependency relationships, etc. d. The container when runtime: The framework creates a container at runtime, which is responsible for the life cycle, injection dependency relationship and service of the management component. 3. Step of the "Annotations for DS" framework: a. Through the annotation of the bidding class: The developer uses the annotation provided by the framework to mark the classes that need to be registered with dependent injection or declaration service. b. Writing configuration file: Developers write a configuration file to specify the detailed information of the service to be registered.This includes component names, dependency relationships, etc. c. Running framework: During the application of the application, the annotation of the framework will scan the category of the annotation to generate the necessary code or configuration. d. Container management: When running, the container is responsible for the life cycle of the management component, and injects dependencies when it is needed. e. Use service: Developers can use registered services by obtaining services in the container. 4. Example code and configuration: Example code: @Component public class MyComponent { @Autowired private AnotherComponent anotherComponent; // ... } @Service public class AnotherComponent { // ... } Configuration file (for example, using Spring's XML configuration): <beans> <bean id="myComponent" class="com.example.MyComponent"/> <bean id="anotherComponent" class="com.example.AnotherComponent"/> </beans> In the above examples, the annotations for `@Component` and@Service` are used to mark the classes that need to be registered with dependent injection or declaration services.Through the note of the `` ANOTHERCOMPONENENT` field in the `mycomponent` class, the` mycomponent` class will be automatically injected. The configuration file defines the detailed information of the service to be registered.In this example, we use Spring's XML configuration to register the `Mycomponent` and` Anothercomponent` as a component. The framework will read the configuration file and create a container at runtime, which is responsible for the life cycle and injecting dependencies of the management component.Developers can use registered services by obtaining services in the container. Summarize: The "Annotations for DS" framework is simplified and enhanced by customized annotations, annotations and containers management, and enhances the process of using dependent injection and declaration services in the Java library.Developers only need to use the annotation of the target class and provide the corresponding configuration files. The framework will automatically process dependency injection and service registration at runtime.