The Hilt Android framework technology in the Java class library (In-Depth Explanation of Hilt Android Framework in Java Class Libraries)

The Hilt Android framework is a dependent injection (DI) framework developed by Google, which aims to simplify the dependency management and object creation process in Android applications.This article will introduce the working principles, core concepts and usage methods of the Hilt Android framework in detail, and provide some Java code examples to help readers better understand. ## What is dependent injection? Before introducing the Hilt Android framework, let's first understand the concept of dependence injection.Dependent injection is a design pattern that is used to manage the dependency relationship between objects.Generally, in the traditional object creation method, objects need to be responsible for creating other objects they depend on themselves.Through the use of dependency injection, the creation process of the object is taken over by the external framework, and the framework will be responsible for analyzing and providing the dependent dependencies. In Android development, dependency injection can help us better organize and manage components in applications, such as Activity, Fragment, Service, etc.By using the dependency injection framework, we can define the dependencies between classes in one place and let the framework solve these dependencies. ## Hilt Android Framework Overview The Hilt Android framework is built based on Dagger 2, which provides a simplified way to achieve dependent injection.Dagger 2 is a powerful dependency injection framework, but it is relatively complicated.The HILT framework provides a more simple and easy -to -use API by establishing a layer of abstraction above Dagger 2. The core concepts in the HILT framework are `@inject` and`@module` annotations.`@Inject` Annotation is used to label the dependency relationship that needs to be parsed by the HILT framework.`@Module` annotations are used to define the creation of dependencies, it tells how the Hilt framework is instantiated and provided by dependent objects. The HILT framework supports different levels of dependencies, including application levels, Activity levels and Fragment levels.These levels correspond to different annotations, such as `@hiltandroidApp`,@AndroidERYPoint` and@fragments. The following is a simple example, demonstrating how to use dependency injection in HILT: @AndroidEntryPoint public class MainActivity extends AppCompatActivity { @Inject ApiService apiService; // ... @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); // Use the injected Apiservice object apiService.doSomething(); // ... } } In the above example, `@AndroidERYPOINT` annotation marks the MaInctivity as the entry point that depends on the injection.`@Inject` Note marked the` Apiservice` field, which tells the HILT framework to provide a dependent object for this field.The `APISERVICE" object is used in the `OnCreate ()" method without manual creation or initialization. ## Installation and configuration Hilt Android framework To use the HILT framework in the Android project, you need to add some configuration and dependencies. First, add the following dependencies in the project's `build.gradle` file: dependencies { implementation "com.google.dagger:hilt-android:2.28-alpha" kapt "com.google.dagger:hilt-android-compiler:2.28-alpha" } Next, mark the application class (usually the subclasses of the `Application`) as the HILT application, such as: @HiltAndroidApp public class MyApplication extends Application { // ... } Then, add appropriate annotations to each component (such as Activity, Fragment, or Service) that needs to be injected, such as: such @AndroidEntryPoint public class MainActivity extends AppCompatActivity { // ... } Finally, make sure that the `@inject` annotation is used in the component to mark the fields or methods that need to be relying on the injection. ## Summarize This article introduces the concept, working principle and basic usage of the Hilt Android framework.As a simplified dependency injection framework, HILT provides an easy way to manage to manage the dependency relationship in Android applications.By using HILT, we can easily organize and maintain our code and make our code more testability and maintenance. I hope that this article will help you understand the Hilt Android framework and provide some practical examples for you when using HILT for dependencies.