Discuss the technical principles of the Junit Vintage Engine framework in the Java library

Discuss the technical principles of the Junit Vintage Engine framework in the Java class library Overview: Junit is one of the most popular unit test frameworks in Java development.However, over time, Junit has continuously updated and upgraded several versions.In order to enable the old version of the Junit test case to perform in the latest Junit version, the Junit Vintage Engine framework came into being.This article will explore the technical principles of the Junit Vintage Engine framework and provide some Java code examples to help readers understand. 1. Junit Vintage Engine Introduction: Junit Vintage Engine is a sub -module released by Junit 5, which aims to support the execution of the old version of the Junit test case on the Junit 5 platform.It provides a bridge that allows Junit 4 and earlier version test cases to run in the environment of Junit 5.This compatibility is very valuable for those who still use the old version of Junit. 2. Junit Vintage Engine's working principle: The core working principle of the Junit Vintage Engine framework is achieved by rewriting the test operator of the Junit 4.Inside the Junit Vintage Engine, it uses the Junit 4's Runner mechanism to perform the old Junit test case.This enables Junit 4's test cases to be compatible with the platform of Junit 5. Suppose we have a test case of the old version of Junit 4, which contains some test methods that use the@test` annotation.When we use Junit 5 to run these test cases, Junit Vintage Engine will intercept these old version of test cases and use the Junit 4 operator to actively execute them. 3. Junit Vintage Engine configuration and use: In order to run the old version of the Junit test case using Junit Vintage Engine, we need to add corresponding dependencies to the pom.xml file of Junit 5.The following is an example: <dependency> <groupId>org.junit.vintage</groupId> <artifactId>junit-vintage-engine</artifactId> <version>5.8.1</version> <scope>test</scope> </dependency> The above dependencies introduce Junit Vintage Engine into our Junit 5 project.Next, we need to ensure that our test class has the `@runwith` annotation of Junit 4, and specify an operator using Junit Vintage Engine.The following is an example: import org.junit.Test; import org.junit.runner.RunWith; import org.junit.runners.JUnit4; @RunWith(JUnit4.class) public class MyJUnit4Tests { @Test public void testMethod() { // Test code } } In the above examples, the annotation of `@runwith (junit4.class)` `Junit tells Junit to use Junit Vintage Engine to perform test cases. 4. Junit Vintage Engine advantage: -The backward compatibility: Junit Vintage Engine allows the old version of the Junit test case to run on the Junit 5 platform without any modification, maintaining backward compatibility. -Slooked transition: For the project using the old version of Junit, you can transition to Junit 5 smoothly through the Junit Vintage Engine without having to modify all test cases at one time. -Stherman resources: Junit Vintage Engine and Junit 5 are seamlessly integrated. You can run the test cases of Junit 5 and Junit 4 in the same Junit test kit. in conclusion: The Junit Vintage Engine framework is rewritten Junit 4's test operator mechanism, so that the old version of the Junit test case can be seamlessly run on the Junit 5 platform.This backward design enables the old version of Junit projects to smoothly transition to Junit 5, and share the resources of Junit 4 and Junit 5 at the same time.Through the introduction of this article, readers have a deeper understanding of the technical principles of the Junit Vintage Engine framework, and can apply this framework in actual projects. I hope this article will help you, thank you for reading!