The basic concepts and usage of the junit interface framework

Junit (that is, the Java language unit testing framework) is a widely used interface test framework that is used to write and execute unit tests for Java programs. Junit's basic concepts include Assertion, Test Class, and Test Method.The assertion is a statement that is used to verify the code. If the expected behavior does not meet, a error will be thrown.The test class is an entity used to organize and manage a set of related test methods, and usually marked with @teest annotations.The test method is the actual method of performing the test operation. It is usually marked with @Test annotations. They must be public, no return value, and there are no parameters. Below is a simple Java code example, demonstrating how to use Junit for unit testing: import static org.junit.Assert.assertEquals; import org.junit.Test; public class CalculatorTest { @Test public void testAddition() { Calculator calculator = new Calculator(); int result = calculator.add(5, 10); assertEquals(15, result); } @Test public void testSubtraction() { Calculator calculator = new Calculator(); int result = calculator.subtract(10, 5); assertEquals(5, result); } } In the above code, we created a Calculator class and wrote two test methods through Junit.In the TestAdDition () method, we created a Calculator object, calling its ADD () method, and using an assertion assertequals () to verify whether the return value is equal to the expected value.Similarly, in the TestSubtraction () method, we conducted a test of subtraction. To run these test methods, you can use the Test Runner of Junit.Junit provides a variety of test operators, such as text runner and IDE integrated operators.You can select the operator to perform the test as needed. Through the Junit interface framework, developers can easily write and maintain unit testing to ensure the quality and reliability of the code.Unit testing can not only improve the testability and maintainability of the code, but also provide timely verification and feedback when the code reconstruction or changes.This will help reduce potential errors and defects, and improve overall software quality.