The technical principles of the Silk Di framework in the Java class library

Silk DI (dependent injection) is a lightweight framework provided in the Java class library, providing Java developers with a flexible and scalable way to manage the dependency relationship between objects.This article will introduce the technical principles of the Silk DI framework and provide some Java code examples to help readers better understand. 1. What is dependent injection? In traditional Java development, objects usually meet their dependence through instantiation.However, this tightly coupling method will cause the testability, maintenance, and scalability of the code.The dependency injection is derived from the object's dependency relationship from the object itself, and it is assigned to external container.In this way, the object only needs to care about its own logic, and does not need to care about how to satisfy its dependence. 2. Basic principles of Silk Di framework The core principle of the Silk DI framework is to manage the dependent relationship between objects through dependency injection containers.It provides a container class that allows developers to inject the dependence of objects into where they need. First of all, we need to mark the fields, construct functions or methods that need to be marked by using the `@inject` annotation.These marked elements represent the demand for a dependencies. public class ExampleService { @Inject private DependencyService dependencyService; // ... } Then, we need to use the@bean` annotation to mark the object that needs to be managed by the container.These objects will be automatically instantiated and injected into other categories. @Bean public class DependencyService { // ... } At the entry point of the application, we need to use the method of `Silk.createinjector () to create a dependent injection container and configure the dependencies in the container. public class Application { public static void main(String[] args) { Injector injector = Silk.createInjector(); ExampleService exampleService = injector.getInstance(ExampleService.class); // ... } } 3. Type binding and dependent analysis The Silk Di framework can automatically analyze and bind dependencies based on the relationship between the class and the interface.This means that you only need to define the relationship between the correct class, and the framework can achieve automatic injection of dependent injection. public class ExampleService { private final DependencyService dependencyService; @Inject public ExampleService(DependencyService dependencyService) { this.dependencyService = dependencyService; } // ... } In the above example, when creating an instance of the `Exampleservice`, the framework will automatically analyze the instance of` DependencyService` and inject it into the constructor.In this way, we can use the `DependencyService` field directly in the` ExampleService`. 4. Life cycle management The Silk Di framework also provides management of the life cycle of the object.Developers can mark the methods that need to be executed when using the `@postConstroct` and@predestroy` annotations to mark when the object creation and destroy. public class ExampleService { @Inject private DependencyService dependencyService; @PostConstruct public void init() { // The initialization logic executed after the object is created } @PreDestroy public void cleanup() { // Cleaning logic executed before the object of the object } // ... } These label methods will be automatically called by the framework during the creation and destruction of the object. Summarize: The Silk DI framework provides a simple and powerful dependency injection mechanism to help developers decouple the dependence relationship.By using the `@inject` and@bean` annotations, developers can define the dependent relationships of objects and let the framework automatically handle their creation and injection.At the same time, by using@PostConstruct` and `@predestroy` annotations, developers can also easily manage the life cycle of the object.