Analysis of Coupling Decoupling in Java Class Libraism
Kouinject is a Java -based lightweight dependency injection (DI) framework, which can help us better decouple the JAVA class library.In this article, we will analyze the decoupled role of the Kouinject framework on the Java class library and provide some Java code examples to illustrate its usage.
1. What is the Coupling Decoupling?
In software development, coupling refers to the mutual dependence between two or more modules.When a module changes can cause other modules to be modified, we can be called coupling.High coupling will cause the code to maintain the poor maintenance, reduce reusability, and increase the risk of modifying the code.
Dealing refers to reducing the dependency between modules, so that the modification of a module will not affect other modules.By decoupled, we can improve the maintenance, testability and scalability of code.
2. Dependency Injection
Dependent injection is a design pattern for dependence between decoupled code.It removes the dependencies of the object from the code, but is responsible for injecting the instance of the dependent object into the code by the external container (such as the framework).Dependent injection can reduce coupling between code and improve the testability and replication of code.
Kouinject provides the following functions:
1. AutoWired: Kouinject can automatically scan and assemble fields or constructors with @AutowIRED annotations to complete the process of dependency injection.
2. Dependency Resolution: Kouinject can analyze the dependencies of the class library and instantiate and inject in the correct order.
3. Lifecycle Management: Kouinject can manage the life cycle of the dependencies to ensure that it is correctly created, used, and releases resources correctly when needed.
4. How to use Kouinject
Below is an example code using the Kouinject framework:
First, we define a dependent Library:
public class Library {
public void doSomething() {
System.out.println("Library is doing something.");
}
}
Then, we define a libraryuser dependent on this type of library:
public class LibraryUser {
@Autowired
private Library library;
public void useLibrary() {
library.doSomething();
}
}
In the above code, we use the @Autowired annotation to mark the library field, indicating that the field needs to be rely on injecting.
Finally, we use the Kouinject framework to complete the injection process:
public class Main {
public static void main(String[] args) {
Injector injector = new DefaultInjector();
LibraryUser libraryUser = injector.getInstance(LibraryUser.class);
libraryUser.useLibrary();
}
}
Through the Kouinject framework, we successfully decoupled the LibraryUser class and the library class, reducing the dependence between code.If we need to modify the dependencies of the library class, we only need to modify the configuration in the injection, without the need to modify the code of the libraryuser class.
Summarize:
Kouinject is a powerful Java dependency injection framework, which can help us better decouple the Java class library.By using Kouinject, we can make the code have better maintenance, testability and scalability, and reduce the risk of code modification.
