HashMap with Flux in Reactive Programming

Question

I have to convert the following code into the non-blocking(asynchronous) process.

EmpController class

@RestController
@RequestMapping("/emp")
public class EmpController {

 private EmployeeRepository empRepo;

@Autowired
public EmpController(EmployeeRepository empRepo)
{
    this.empRepo=empRepo;
}

   @PostMapping("/save/all")
    @Consumes({MediaType.APPLICATION_JSON})
    public void saveEmpAll(@RequestBody List<Employee> emps)
    {
        empRepo.saveEmpAll(emps);
    }
}

EmployeeRepository class

@Repository
public class EmployeeRepository implements EmployeeDAO {

 @Override
    public void saveEmpAll(List<Employee> emps) {

        Map<Long,Employee> employees=new HashMap<>();

        emps.forEach(emp->{
            emp.setDate(new Date());
            employees.put(emp.getId(),emp);
        });
        hashOperations.putAll("EMP",employees);
    }

}

Use Reactive Programming with Spring Webflux

controller

@PostMapping("/save/all")
    @Consumes({MediaType.APPLICATION_JSON})
    public void saveEmpAll(@RequestBody Flux<Employee> emps)
    {
        emps.collectMap(e->{
           e.setDate(new Date());
           // todo.............( can I do like this? is it the right way?)
        });
    }

ropository

  @Override
    public void saveEmpAll(Map<Long,Employee> employees) {
        hashOperations.putAll("EMP",employees);
    }

is there any other way to create HashMap and put values into it in an asynchronous way with Flux?