Detailed explanation of the technical principles of Javax Inject TCK framework in the Java class library
Detailed explanation of the technical principles of the Javax Inject TCK framework
introduce
Javax Inject TCK (technical compatibility kit) is a framework in the Java class library that is used to test whether the Dependency Injection framework complies with the JSR-330 specification.This article will introduce the technical principles of the Javax Inject TCK framework, and provide some Java code examples to help readers better understand.
Dependence
Dependent injection is a design pattern that is used to achieve loose coupling relationship between components.It is injected into the component by injecting the dependencies required by the component, instead of the component created or obtained the dependencies, thereby realizing the reassessment and testability of the code.
Jsr-330 specification
The JSR-330 is part of the Java specification request, which aims to define the best practice to execute dependency injection in the Java application.It defines a set of annotations and interfaces for identification and management dependencies.The Javax Inject TCK framework aims to test whether the dependent injection framework meets these specifications.
Technical principle of Javax Inject TCK framework
The Javax Inject TCK framework is used to verify whether the dependent injection framework complies with the JSR-330 specification through a series of test cases.It uses reflexes and dynamic proxies to check and operate the objects in the injection framework.
The following are some key technical principles of the Javax Inject TCK framework:
1. Reflex: Javax Inject TCK framework uses the reflection mechanism to check the annotation information of the class and methods.It can obtain an annotation, check the attribute value of the annotation, and obtain the method and field of the class at runtime.
2. Dynamic proxy: Javax Inject TCK framework uses dynamic proxy to create and manage objects in the injection framework.It delays the creation and injection of dependencies through proxy objects.
3. Note processor: The Javax Inject TCK framework uses an annotation processor to process the annotation of the relying on the injection frame.It can extract the annotation information and generate corresponding test cases according to the rules defined.
Java code example
Below is a simple Java code example, demonstrating how to use the Javax Inject TCK framework to test some functions that depend on the injection framework:
public class MyDependency {
private String name;
@Inject
public MyDependency(@Named("name") String name) {
this.name = name;
}
public String getName() {
return name;
}
}
public class MyDependencyTest {
@Inject
@Named("name")
private String name;
@Test
public void testDependencyInjection() {
MyDependency dependency = new MyDependency(name);
assertEquals(name, dependency.getName());
}
}
public class DependencyInjectionTestSuite {
public static TestSuite suite() {
TestSuite suite = new TestSuite();
suite.addTestSuite(MyDependencyTest.class);
return suite;
}
}
public class Main {
public static void main(String[] args) {
TestRunner.run(DependencyInjectionTestSuite.suite());
}
}
In this example, we define a class called `MyDependency`, which is used by the dependency injection framework that it is tested.`MyDependency` has a constructor that uses the`@inject` annotation labeling, which accepts a string parameter with the `@named` annotation mark.We also define a test class called `myDependencyTest`. It uses the Javax Inject TCK framework to verify whether the dependent injection framework is correctly injected.
in conclusion
The Javax Inject TCK framework can effectively test whether the dependent injection framework meets the JSR-330 specification by using reflex, dynamic proxy and annotation processor.This article provides a simple Java code example to demonstrate how to use the framework to test the function of relying on the injection framework.It is hoped that readers can better understand the technical principles of the Javax Inject TCK framework through this article.