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I am creating an application backend as with RDF Database.

I am using Jena TDB as backend. I am getting this exception

com.hp.hpl.jena.sparql.JenaTransactionException: Currently in a transaction (location:/home/visittoravi/Documents/Store/DB/Tutor/)

Here is my code in this method exception occurs i have marked it with comments- 

public UserDetails loadUserByUsername(String email)
            throws UsernameNotFoundException {
        org.springframework.security.core.userdetails.User authUser = null;
        logger.info("Getting user - " + email);
        Dataset ds = datasetManager.getDs();
        ds.begin(ReadWrite.READ);  // Exception is being thrown here
        try {
            User user = logUserIn(email);
            if (user == null) {
                System.out.println("User not found");
                throw new UsernameNotFoundException(email);
            }
            logger.info("role = " + user.getRole());
            List<GrantedAuthority> authorities = new ArrayList<GrantedAuthority>();
            authorities.add(new SimpleGrantedAuthority(user.getRole()));
            authUser = new org.springframework.security.core.userdetails.User(
                    email, user.getPassword(), true, true, true, true,
                    authorities);
            ds.commit();
        } catch (Exception ex) {
            ex.printStackTrace();
            logger.error(ex);
            ds.abort();
        } finally {
            ds.end();
        }
        return authUser;
    }

datasetManager.getDs() method - 

public Dataset getDs() {
        if (ds == null) {
            logger.log(Priority.INFO, "Creating TDB dataset at : " + dir);
            ds = TDBFactory.createDataset(dir);
            getOntModel();
        }
        return ds;
    }

getOntModel() method - 

public OntModel getOntModel() {
        if (ontModel == null) {
            Dataset ds = getDs();
            ds.begin(ReadWrite.WRITE);
            try {
                ontModel = ModelFactory.createOntologyModel(
                        OntModelSpec.OWL_DL_MEM_RULE_INF, ds.getDefaultModel());
                createAdminData(ds);
                createAllOntClasses();
                createAllProperties();
                ds.commit();
            } catch (Exception ex) {
                ex.printStackTrace();
                ds.abort();
            } finally {
                ds.end();
            }
        }
        return ontModel;
    }

createAdminData method - 

private void createAdminData(Dataset ds) {
        Resource admin = getDs().getDefaultModel().createResource(
                rnamespace + "User1");
        admin.addLiteral(VCARD.UID, 1l);
        admin.addLiteral(VCARD.FN, "Admin");
        admin.addLiteral(VCARD.NAME, "Admin");
        admin.addLiteral(VCARD.EMAIL, "visittoravi@gmail.com");
        admin.addLiteral(VCARD.ROLE, "ADMIN");
        admin.addLiteral(VCARD.KEY, "password");
    }

again in createAllOntClasses() and createAllProperties(); i am creating some ontclasses and properties using ontModel.

As you can see in getDs() method i have created a write transaction and i have also included end transaction(ds.end()). and all the db writing part in getOntModel() method is being reflected in database i checked it in fuseki. and after that i am creating a read transaction and it's throwing this exception.

Please help to identify the problem. Also if you have a better way to deal with such scenario like initializing db at context startup in spring mvc.

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