12. Build Delete Employee REST API

EmployeeService

    void deleteEmployee(Long employeeId);

EmployeeServiceImpl

    @Override
    public void deleteEmployee(Long employeeId) {

        // we need to check whether employee with given id is exist in DB or not
        Employee existingEmployee = employeeRepository.findById(employeeId)
                .orElseThrow(() -> new IllegalArgumentException(
                        "Employee not exists with a given id : " + employeeId)
                );

        employeeRepository.deleteById(employeeId);
    }

EmployeeController

    // build delete employee REST API
    // http://localhost:8080/api/employees/1
    @DeleteMapping("{id}")
    public ResponseEntity<String> deleteEmployee(@PathVariable("id") long id){

        // delete employee from DB
        employeeService.deleteEmployee(id);

        return new ResponseEntity<String>("Employee deleted successfully!.", HttpStatus.OK);
    }