updated code

src/main/java/com/poc/web/mapper/EmployeeMapper.java

@@ -15,7 +15,7 @@ public class EmployeeMapper implements EntityMapper {
 	public Object mapPojoToEntity(Object pojo) {
 		Optional<Object> obj=Optional.ofNullable(pojo);
 		if(obj.isPresent()) {
-			Emp emp=(Emp)pojo;
+			Emp emp=(Emp)obj.get();
 			Employee employee=new Employee();
 			employee.setDeptId(emp.getDeptId());
 			employee.setDeptName(emp.getDeptName());
@@ -37,7 +37,7 @@ public class EmployeeMapper implements EntityMapper {
 		Optional<Object> obj=Optional.ofNullable(entity);
 		if(obj.isPresent()) {
 			
-			Employee employee=(Employee)entity;
+			Employee employee=(Employee)obj.get();
 			Emp emp=new Emp();
 			emp.setDeptId(employee.getDeptId());
 			emp.setDeptName(employee.getDeptName());

src/main/java/com/poc/web/service/EmployeeServiceImpl.java

@@ -23,19 +23,22 @@ public class EmployeeServiceImpl implements EmployeeService {
 
 	@Override
 	public Mono<Emp> findByEmpId(Long empId) {
-		return Mono.justOrEmpty((Emp) employeeMapper.mapEntityToPojo(empMongoRepository.findByEmpId(empId)));
+		Mono<Employee> monoEmployee = empMongoRepository.findByEmpId(empId);
+		Mono<Emp> monoEmp = monoEmployee.map(e -> employeeMapper.mapEntityToPojo(e)).map(e -> (Emp) e);
+		return monoEmp;
 	}
 
 	@Override
 	public Mono<Emp> findById(String id) {
-		return Mono.just(
-				(Emp) employeeMapper.mapEntityToPojo(empMongoRepository.findById(id).defaultIfEmpty(new Employee())));
+		Mono<Employee> monoEmployee = empMongoRepository.findById(id);
+		Mono<Emp> monoEmp = monoEmployee.map(e -> employeeMapper.mapEntityToPojo(e)).map(e -> (Emp) e);
+		return monoEmp;
 	}
 
 	@Override
 	public Flux<Emp> findAll() {
-		Flux<Employee> list=empMongoRepository.findAll();
-		Flux<Emp> empList = list.map(e ->employeeMapper.mapEntityToPojo(e)).map(e -> (Emp) e);
+		Flux<Employee> list = empMongoRepository.findAll();
+		Flux<Emp> empList = list.map(e -> employeeMapper.mapEntityToPojo(e)).map(e -> (Emp) e);
 
 		return empList;