Use Javax Inject to achieve the best practice of decoupling

Use Javax Inject to achieve the best practice of decoupling In software development, decoupling is an important design principle, which can make the code more flexible, maintained and scalable.Javax Inject is a standard specification of the Java dependencies inject, which provides a simple and flexible way to achieve decoupling. Dependent injection refers to the way to remove the dependencies from the code and manage and inject these dependencies through external containers.Javax Inject uses annotations to mark and automatically manage dependencies to realize coupling. The following is the best practice of decoupling with Javax Inject: 1. Define dependency: First of all, define the dependency relationship that needs to be injected.This can be achieved by using @inject annotations in a class that needs to be injected.For example, we have an UserService interface and an UserServiceIMPL implementation class: public interface UserService { void saveUser(User user); } public class UserServiceImpl implements UserService { @Override public void saveUser(User user) { // Save user logic } } 2. Create a dependent injection container: Next, you need to create a dependent injection container to manage the dependence relationship.Javax Inject provides a javax.inject.injector interface, which we can use it to create a container.For example, dependent injection containers implemented using Google Guice: import com.google.inject.Guice; import com.google.inject.Injector; public class App { public static void main(String[] args) { Injector injector = Guice.createInjector(new AppModule()); UserService userService = injector.getInstance(UserService.class); // Use userService to operate } } 3. Configuration dependencies: When creating a container, you need to configure dependencies.This can be achieved by creating a module containing a dependent relationship.For example, using Google Guice's Module class: import com.google.inject.AbstractModule; public class AppModule extends AbstractModule { @Override protected void configure() { bind(UserService.class).to(UserServiceImpl.class); } } In the above example, we bind the UserService interface to the UserServiceImpl class, so that when we request the UserService instance, the container will automatically create and inject the UserServiceIMPL instance. Through the above steps, we successfully use the Javax Inject to realize the coupling.We no longer need to expand the dependencies in the code, but instead inject the management dependencies through injecting the container.In this way, we can easily change and expand the dependencies without modifying the logic of code. To sum up, using Javax Inject can help us realize the decoupling of code and improve the flexibility and maintenance of the code.By defining dependency relationships, creating dependency injection containers and configuration dependencies, we can better organize and manage the dependency relationship in the management code.At the same time, Javax Inject also provides more advanced features, such as dependency scores and optional dependencies, so that we can manage dependence more flexible. references: - [Java Dependency Injection With Google Guice](https://www.baeldung.com/java-google-guice) - [Understanding Javax Inject](https://www.baeldung.com/java-ee-cdi) - [Dependency Injection with CDI](https://www.baeldung.com/java-cdi)