Spring, @Autowired NullPointerException

package main.com.java.dao.implementation;

import java.util.List;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.query.Query;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;
import org.springframework.transaction.annotation.Transactional;

import main.com.java.dao.interfaces.AccountDAO;
import main.com.java.entity.Account;;import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Root;

@Repository
public class AccountDAOImpl implements AccountDAO{

	@Autowired
	private SessionFactory sessionFactory;
	
	public Session createCurrentSession(SessionFactory sessionFactory){
		Session session = sessionFactory.getCurrentSession();
		return session;
		
	}
	
	@Override
	@Transactional
	public List<Account> getAccountList() {		
		Query<Account> theQuery = createCurrentSession(sessionFactory).createQuery("from Account", Account.class);		
		List<Account> accountsList = theQuery.getResultList();
		
		return accountsList;
	}

	@Override
	public Account getAccountById(int id) {
		try {			
			return createCurrentSession(sessionFactory).get(Account.class, id);		
		} catch (Exception e) {
			e.printStackTrace();
			return null;
		}

	}

	@Override
	public void addAccount(Account theAccount) {
		try {
			Session currentSession = sessionFactory.getCurrentSession();
			currentSession.saveOrUpdate(theAccount);
			currentSession.clear();
		} catch (Exception e) {
			e.printStackTrace();
		}
		
	}

	@Override
	public void updateAccount(Account theAccount) {
		try {
			createCurrentSession(sessionFactory).saveOrUpdate(theAccount);
		} catch (Exception e) {
			e.printStackTrace();
		} 
	}

	@Override
	public void removeAccount(Account theAccount) {
		try {
			createCurrentSession(sessionFactory).remove(theAccount);
		} catch (Exception e) {
			e.printStackTrace();
		} 
		
	}

	@Override
	public void saveAccount(Account theAccount) {
		// get hibernate session
		Session currentSession = sessionFactory.getCurrentSession();
		
		//save the account 
		currentSession.saveOrUpdate(theAccount);
		currentSession.clear();
	}

	@Override
	public List<String> getAccountNumberList(){

		CriteriaBuilder builder = sessionFactory.getCurrentSession().getCriteriaBuilder();
		CriteriaQuery<String> query = builder.createQuery(String.class);
        System.out.print("query = " + query);
		Root<Account> root = query.from(Account.class);
		query.select(root.get("accountNumber"));
	    Query<String> theQuery = createCurrentSession(sessionFactory).createQuery(query);

		return theQuery.getResultList();
	}

	
}

package main.com.java.service.domain.implementation;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import main.com.java.dao.interfaces.AccountDAO;
import main.com.java.entity.Account;
import main.com.java.service.domain.interfaces.AccountService;

import java.util.List;

@Service
public class AccountServiceImpl implements AccountService {

    @Autowired
    AccountDAO accountDAO;

	@Override
	@Transactional
	public void addAccount(Account theAccount) {
		accountDAO.addAccount(theAccount);
	}

	@Override
    @Transactional
	public List<String> getAccountNumberList(){
		System.out.print("AccountServiceImpl");
	    return accountDAO.getAccountNumberList();
    }

}

package main.com.java.service.business.generators;

import main.com.java.service.domain.interfaces.AccountService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.util.List;
import java.util.Random;

@Service
public class AccountNumberGenerator {

    @Autowired
    AccountService accountService;

    @Transactional
    public String generateAccountNumber(){
        String potentialAccountNumber = generatePotentialAccountNumber();
        if(checkIsAccountNumberIsFree(potentialAccountNumber)){
           return potentialAccountNumber;
        }else{
            while(checkIsAccountNumberIsFree(potentialAccountNumber)){
                potentialAccountNumber = generatePotentialAccountNumber();
            }
            return generatePotentialAccountNumber();
        }
    }

    private String generatePotentialAccountNumber(){
        String checksum = generateChecksum();
        String bankNumber = "12853321";
        String clientNumber = generateClientNumber();
        String accountNumber = "";

        StringBuilder stringBuilder = new StringBuilder(accountNumber);
        stringBuilder.append(checksum).append(bankNumber).append(clientNumber);


        return stringBuilder.toString();
    };


    private  boolean checkIsAccountNumberIsFree(String potentialAccountNumber){
        List<String> occupiedAccountNumberList = accountService.getAccountNumberList();
        for (String occupiedAccountNumber : occupiedAccountNumberList) {
            if(potentialAccountNumber.equals(occupiedAccountNumber)){
                return Boolean.FALSE;
            }
        }
        return Boolean.TRUE;

    };

    private static String generateChecksum(){
        Random random = new Random();
        String checksum = "";
        StringBuilder stringBuilder = new StringBuilder(checksum);

        for (int i =0; i<2; i++){
            stringBuilder.append(random.nextInt(10));
        }
        checksum = stringBuilder.toString();
        return checksum;
    };

    private String generateClientNumber(){
        Random random = new Random();
        String clientNumber = "";
        StringBuilder stringBuilder = new StringBuilder(clientNumber);

        for (int i =0; i<16; i++){
            stringBuilder.append(random.nextInt(10));
        }
        clientNumber = stringBuilder.toString();
        return clientNumber;
    }

}

List<String> occupiedAccountNumberList = accountService.getAccountNumberList();