In -depth understanding of the core concept and working principle of the Autowire framework

AUTOWIRE is a commonly used framework in Java development, which provides a method of dependent injection to manage the relationship between objects.Before understanding the core concept and working principles of the AUTOWIRE framework, let's first understand the concept of dependent injection. Dependent injection is a design pattern that to inject other objects that objects depend on them into their constructor, attributes, or methods to achieve collaboration between objects.The advantage of this method is that it can reduce the coupling between objects and improve the maintenance and testability of the code. The Autowire framework is designed to achieve injecting.It finds the corresponding objects and automatically injected into the corresponding place by scanning and parsing the annotations in the application (such as@AutowIred,@Component, etc.).Let's discuss the core concepts and working principles of the Autowire framework in detail. 1. Core concept The core concept of the Autowire framework includes: -Injecting Point: Refers to the object that needs to be injected, it can be a constructor, attribute or method. -DEPENDENCY: Refers to the injected object, which can be an instance or interface implementation class of other categories. -CONTAINER: The central component responsible for the dependent relationship between management and maintenance objects. 2. Working principle The working principle of the Autowire framework is as follows: -Scan: Autowire framework scan the annotation in the application, find a class and method with @Autowired annotations. -Etties: The framework will analyze the class marked by the @Autowired annotation, and find the corresponding dependencies. -Colon: The framework will create a dependent object and save it in a container. -Plip: The framework will automatically inject the created dependent object into the required injection point. The following is a simple Java code example, used to demonstrate the use of the Autowire framework: @Component public class UserService { private UserRepository userRepository; @Autowired public UserService(UserRepository userRepository) { this.userRepository = userRepository; } // ... } @Component public class UserRepository { // ... } In the above example, there is an UserRePOSITORY type dependencies in the UserService class, which is injected through the @Autowired annotation of the constructed method.When the application starts, the Autowire framework will automatically scan the class marked by the @Autowired annotation, analyze their dependencies, and create the corresponding objects. Summarize: The Autowire framework is a Java framework for realizing the injecting. By scanning and analyzing the annotations in the application, the dependency relationship between objects is automatically injected.By understanding the core concept and working principle of the Autowire framework, we can better use the framework to improve the maintenance and testability of the code.