how to test microservice using spring boot and maven

I am using spring boot and maven framework to set up microservice. Now i want to do some tests to make sure they are working properly. However, I am not sure how i should invoke them when i run the test. Or is my way of testing micro service correct? Thanks in advance

i have tried to invoke the micro services in the test java file but failed

this is the interface

public interface EmployeeRepository extends JpaRepository<Employee, Integer> {
...
    @Modifying
    @Query(value = "insert into Employee (id,fullname) values (:id,:fullname)",
            nativeQuery = true)
    void insertEmployee(@Param("id") int id,@Param("fullname") String fullname);
...
}

this is the class that handles mappings

public class EmployeeResource {
    @Autowired
    EmployeeRepository usersRepository;
    @PostMapping(value="/add")
    @Transactional
    public void add(...){...}
}

I tried to invoke them by using this but failed because database is not updated

1

    @Test
    @Transactional
    public void testInsert(){
        EmployeeResource er = new EmployeeResource();
        er.add(999,"test");
    ArrayList<Employee> test = (ArrayList<Employee>)er.find(999);


    }

2

    @Test
    @Transactional
    public void testInsert(){
        EmployeeRepository usersRepository;
        usersRepository.insertEmployee(999,"test");
    ArrayList<Employee> test = 
        (ArrayList<Employee>)usersRepository.findEmp(999);


    }