Here we will see one complete example of JUnit testing using POJO class, Business logic class, and a test class, which will be run by the test runner.

Create EmployeeDetails.java in C:>JUNIT_WORKSPACE, which is a POJO class.

public class EmployeeDetails {

   private String name;
   private double monthlySalary;
   private int age;
   
   /**
   * @return the name
   */
	
   public String getName() {
      return name;
   }
	
   /**
   * @param name the name to set
   */
	
   public void setName(String name) {
      this.name = name;
   }
	
   /**
   * @return the monthlySalary
   */
	
   public double getMonthlySalary() {
      return monthlySalary;
   }
	
   /**
   * @param monthlySalary the monthlySalary to set
   */
	
   public void setMonthlySalary(double monthlySalary) {
      this.monthlySalary = monthlySalary;
   }
	
   /**
   * @return the age
   */
   public int getAge() {
      return age;
   }
	
   /**
   * @param age the age to set
   */
   public void setAge(int age) {
      this.age = age;
   }
}

EmployeeDetails class is used to −

• get/set the value of employee”s name.
• get/set the value of employee”s monthly salary.
• get/set the value of employee”s age.

Create a file called EmpBusinessLogic.java in C:>JUNIT_WORKSPACE, which contains the business logic.

public class EmpBusinessLogic {
   // Calculate the yearly salary of employee
   public double calculateYearlySalary(EmployeeDetails employeeDetails) {
      double yearlySalary = 0;
      yearlySalary = employeeDetails.getMonthlySalary() * 12;
      return yearlySalary;
   }
	
   // Calculate the appraisal amount of employee
   public double calculateAppraisal(EmployeeDetails employeeDetails) {
      double appraisal = 0;
		
      if(employeeDetails.getMonthlySalary() < 10000){
         appraisal = 500;
      }else{
         appraisal = 1000;
      }
		
      return appraisal;
   }
}

EmpBusinessLogic class is used for calculating −

• the yearly salary of an employee.
• the appraisal amount of an employee.

Create a file called TestEmployeeDetails.java in C:>JUNIT_WORKSPACE, which contains the test cases to be tested.

import org.junit.Test;
import static org.junit.Assert.assertEquals;

public class TestEmployeeDetails {
   EmpBusinessLogic empBusinessLogic = new EmpBusinessLogic();
   EmployeeDetails employee = new EmployeeDetails();

   //test to check appraisal
   @Test
   public void testCalculateAppriasal() {
      employee.setName("Rajeev");
      employee.setAge(25);
      employee.setMonthlySalary(8000);
		
      double appraisal = empBusinessLogic.calculateAppraisal(employee);
      assertEquals(500, appraisal, 0.0);
   }

   // test to check yearly salary
   @Test
   public void testCalculateYearlySalary() {
      employee.setName("Rajeev");
      employee.setAge(25);
      employee.setMonthlySalary(8000);
		
      double salary = empBusinessLogic.calculateYearlySalary(employee);
      assertEquals(96000, salary, 0.0);
   }
}

TestEmployeeDetails class is used for testing the methods of EmpBusinessLogic class. It

• tests the yearly salary of the employee.
• tests the appraisal amount of the employee.

Next, create a java class filed named TestRunner.java in C:>JUNIT_WORKSPACE to execute test case(s).

import org.junit.runner.JUnitCore;
import org.junit.runner.Result;
import org.junit.runner.notification.Failure;

public class TestRunner {
   public static void main(String[] args) {
      Result result = JUnitCore.runClasses(TestEmployeeDetails.class);
		
      for (Failure failure : result.getFailures()) {
         System.out.println(failure.toString());
      }
		
      System.out.println(result.wasSuccessful());
   }
} 

Compile the test case and Test Runner classes using javac.

C:JUNIT_WORKSPACE>javac EmployeeDetails.java 
EmpBusinessLogic.java TestEmployeeDetails.java TestRunner.java

Now run the Test Runner, which will run the test case defined in the provided Test Case class.

C:JUNIT_WORKSPACE>java TestRunner

Verify the output.

true