In-depth understanding of the technical principles of the Junit Vintage Engine framework in the Java library (In-Depth UndersTnding of the Technical Principles of Junit Vintine Framework in Java Class Librarys)

In -depth understanding of the technical principles of the Junit Vintage Engine framework in the Java class library Overview: Junit is a widely used Java unit testing framework that helps developers write reliable and high -quality test code.In the Java class library, the Junit Vintage Engine framework is an important component in the Junit 5.x version, which allows developers to run the old version of the Junit 3.x test code on Junit 4.x.This article will explore the technical principles of the Junit Vintage Engine framework and how to use it in the Java code. Technical principle: The core principle of the Junit Vintage Engine framework is to integrate the Junit 3.x test code with the Junit 5.x test framework through the adapter mode.Junit 3.x test code is written based on the old version of the Junit 3.x version of the Junit framework, and the Junit 5.X test framework is the latest version of Junit, which has many new functions and improvements.Due to the differences between Junit 3.x and Junit 5.x, the old version of the Junit 3.x test code cannot be directly run.The Junit Vintage Engine framework solves this problem and provides an intermediate layer that allows the old version of the Junit 3.x test code to run correctly in the Junit 5.x test framework. The workflow of the Junit Vintage Engine framework is as follows: 1. Find the Junit 3.x test code: Junit Vintage Engine framework will first find Junit 3.x test code in the specified test class.It checks whether the test class extends the testcase class in the Junit 3.x version, and the test method uses the @Test annotation in the Junit 3.x version.If the test class meets these conditions, the Junit Vintage Engine framework will deal with this class. 2. Construct a adapter: Junit Vintage Engine framework creates a adapter for the found Junit 3.x test class.The adapter is a class that implements the TESTENGINE interface that implements the Junit 5.x. It can convert the Junit 3.x test class to the form of understanding of the Junit 5.x test framework.The adapter will convert Junit 3.x test methods into a dynamic test of Junit 5.x and provide appropriate initialization and cleaning code. 3. Operation test: Once the adapter is constructed, the Junit Vintage Engine framework will use the Junit 3.x test code to run the adaptive Junit 3.x test code with the Junit 5.x test engine.The test engine will perform testing according to the execution model of Junit 5.x, including test parallelism, order, and life cycle management. Java code example: Here are a simple Java code example to demonstrate how to use the Junit Vintage Engine framework: import junit.framework.TestCase; import org.junit.Test; // junit 3.x test class public class JUnit3Test extends TestCase { @Test public void testAddition() { int result = 2 + 2; assertEquals(4, result); } @Test public void testSubtraction() { int result = 4 - 2; assertEquals(2, result); } } // junit 5.x test class import org.junit.jupiter.api.Test; import org.junit.platform.runner.JUnitPlatform; import org.junit.runner.RunWith; @RunWith(JUnitPlatform.class) public class JUnit5Test { @Test public void testMultiplication() { int result = 2 * 2; assertEquals(4, result); } @Test public void testDivision() { int result = 4 / 2; assertEquals(2, result); } } In the above example, the Junit3Test class is a test class that follows the Junit 3.x specification, which contains two test methods.The Junit5Test class is a test class that follows the Junit 5.x specification, and also includes two test methods.By placing the Junit 3.x test code with the Junit 5.x test code in the same project, you can use the Junit Vintage Engine framework to perform these two different versions of testing at the same time. in conclusion: Junit Vintage Engine framework is an important component in the Junit 5.x version, allowing developers to run the old version of the Junit 3.x test code on Junit 4.x.This article explains the technical principles of the Junit Vintage Engine framework, and provides a simple Java code example to demonstrate how to use the framework.By understanding the principle of the Junit Vintage Engine framework, developers can better use the new features and improvements of Junit 5.x, and retain and run the old version of the Junit 3.x test code.