The technical principles of ActiveJ: Inject framework in the Java class library
ActiveJ: Technical Principles of Inject Framework
ActiveJ is a high -performance Java class library that provides many powerful functions and tools to make developers more easily build maintenance and scalable applications.One of the core components is the ActiveJ: Inject framework. It is a lightweight dependency injection (DI) framework that is used to manage and solve the dependency relationship between application components.In this article, we will thoroughly study the technical principles of the ActiveJ: Inject framework, and provide some Java code examples to illustrate its usage.
1. Display binding (Explicit Binding)
The ActiveJ: Inject framework defines the dependency relationship between the management of the components by displaying binding.This means that all dependencies need to be explicitly declared and defined in the frame, rather than implicitly inferring.This method can increase the readability and maintenance of code, making it easier for developers to understand and manage the dependency between management components.
Here are examples of explicit binding using ActiveJ: Inject framework:
public interface Service {
void execute();
}
public class ServiceImpl implements Service {
@Override
public void execute() {
System.out.println("Executing service...");
}
}
@Inject
public class Controller {
private final Service service;
public Controller(Service service) {
this.service = service;
}
public void handleRequest() {
service.execute();
}
}
public static void main(String[] args) {
Injector injector = Injector.of(
binder -> binder.bind(Service.class).to(ServiceImpl.class)
);
Controller controller = injector.getInstance(Controller.class);
controller.handleRequest();
}
In the above example, we created an injectioner by calling the `Injector.of ()" method, and then explicitly bind the `Service` interface to the` ServiceImpl` class.Finally, we obtained an instance instance by calling the method of calling `injector.getInstance ()` `).
2. Lifecycle Management
ActiveJ: Inject framework supports specific operations in the life cycle of the component.These operations can be performed when the component creation and destruction, such as performing initialization methods after creating components, or performing cleaning operations before destruction of components.This can ensure that the series of work before and after using the components are properly processed, such as opening and closing the connection, initialization and release of resources.
The following is an example of using ActiveJ: Inject framework for life cycle management:
@Inject
@Singleton
public class DatabaseConnection {
public DatabaseConnection() {
// Initialize database connection
}
public void open() {
// Open the database connection
}
public void close() {
// Close the database connection
}
@PostConstruct
public void init() {
open();
}
@PreDestroy
public void cleanup() {
close();
}
}
public static void main(String[] args) {
Injector injector = Injector.of(
binder -> binder.bind(DatabaseConnection.class)
);
DatabaseConnection connection = injector.getInstance(DatabaseConnection.class);
// Use the database to connect to perform operation
injector.close();
}
In the above example, we used the `@singleton` annotation to mark the` databaseconnection` class as a single component.In the constructor of this class, we execute the initialization of the database connection.By using@PostConstrut` and@@Predestroy`, we define the method of implementing and destroying the component creation and destroying.In the `Main` method, we obtained an instance of a` databaseconnection`, and executed some database operations, and then manually called the `injector.close () method to close the injection and process the cleaning operation of the component at the end of the program.
3. Limited character (qualifiers)
ActiveJ: Inject framework supports the use of limited character to distinguish and select different components to implement.Limited symbols are an annotation that can be attached to the component to provide more information to help the framework understand how to solve the dependent relationship.
The following is an example of a limited character using ActiveJ: Inject framework:
import java.lang.annotation.*;
@Retention(RetentionPolicy.RUNTIME)
@Qualifier
public @interface Production {
}
@Retention(RetentionPolicy.RUNTIME)
@Qualifier
public @interface Development {
}
@Inject
public class ServiceImpl implements Service {
@Override
public void execute() {
System.out.println("Executing service...");
}
}
@Inject
@ServiceQualifier(Production.class)
public class ProductionController {
private final Service service;
public ProductionController(Service service) {
this.service = service;
}
public void handleRequest() {
service.execute();
}
}
@Inject
@ServiceQualifier(Development.class)
public class DevelopmentController {
private final Service service;
public DevelopmentController(Service service) {
this.service = service;
}
public void handleRequest() {
service.execute();
}
}
public static void main(String[] args) {
Injector injector = Injector.of(
binder -> {
binder.bind(Service.class).to(ServiceImpl.class);
binder.bind(ProductionController.class).qualifiedBy(Production.class);
binder.bind(DevelopmentController.class).qualifiedBy(Development.class);
}
);
ProductionController productionController = injector.getInstance(ProductionController.class);
productionController.handleRequest(); // 输出: Executing service...
DevelopmentController developmentController = injector.getInstance(DevelopmentController.class);
developmentController.handleRequest(); // 输出: Executing service...
}
In the above example, we use the `@Production` and@Development` annotations to create two limited characters.Then, we used the `@Servicequalifier` `@servicequalifier` on the `ProductionController` and the` DevelopmentController` class, and select the injected `Service` in the constructor.In the configuration of the injection, we use the method of `binder.bind (). Qualifydby ()` to associate different controllers with the corresponding limited character.Finally, we can obtain an instance with corresponding limited symbols by calling the method by calling the `Injector.getInstance () method, and call the method.
The technical principles of the ActiveJ: The technical principles of the Inject framework revolves around the concept of explicit binding, life cycle management and limited character, which can help developers better manage and solve the dependency relationship between components.By using the ActiveJ: Inject framework, we can build maintenance and scalable applications and improve the readability and maintenance of code.
(This article is a fictitious content that cannot be executed or running java code)
