Use the test bundle framework in the Java class library for unit test

Use the test bundle framework in the Java class library for unit test During the software development process, unit testing is a vital task.It can help developers verify the correctness of its code and ensure that the software can still work as expected after changes.In order to simplify the writing and management of unit testing, the Java class library provides many test frameworks, one of which is the commonly used test framework is Junit. Junit is an open source Java test framework that provides a set of tools and methods for writing and running unit testing.Using Junit, developers can easily create test cases and execute these test cases, thereby effectively testing their code. The following will show how to use Junit for unit testing through a sample.Suppose we have a class named Calculator, which provides some basic mathematical computing functions, such as addition, subtraction, multiplication, and division.We want to write some test cases to verify whether the various methods of the Calculator class work in accordance with the expected work. First, we need to introduce the Junit framework in the project.We can use Maven or Gradle and other construction tools to add Junit to our project dependence. <dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.13.2</version> <scope>test</scope> </dependency> </dependencies> We can then write test cases.Create a new class called CalculatorTest, and use the@test` annotation mark each test method.In each test method, we can use various assertions to verify whether our code logic is correct. import org.junit.Test; import static org.junit.Assert.*; public class CalculatorTest { @Test public void testAdd() { Calculator calculator = new Calculator(); int result = calculator.add(2, 3); assertEquals(5, result); } @Test public void testSubtract() { Calculator calculator = new Calculator(); int result = calculator.subtract(5, 3); assertEquals(2, result); } // More test methods ... } In this example, we wrote two test methods to verify the correctness of the method of `ADD () and` Subtract () `.We created a Calculator object and used the object to call the corresponding method.Then, we use the `Assertequals ()` `Assertequals ()` we assert whether the return result of the method is equal to the expected value. Finally, we can use Junit to run our test cases.We can use the Junit operator in the IDE to perform testing, or use the `MVN Test` or Gradlew Test` commands in the constructive tool to perform the test.Junit will execute each of our test methods and report the test results and any failure. By using the test binding framework in the Java class library, such as Junit, developers can write and perform unit tests more easily.This helps improve the quality of code, reduce errors, and enhance the reliability of software.