CODEWITHSUNDEEP
javaspringdao
Malena T
Malena T

Reputation: 371

Spring EntityManager is Closed

I want to search for username which is not unique. I implemented below code in DAO and it gives error HTTP Status 500 - Request processing failed; nested exception is java.lang.IllegalStateException: EntityManager is closed. 

@PersistenceContext
    private EntityManager entityManager;

    @Transactional
    public void save(Client client) {
        entityManager.persist(client);
    }

public Client findByUsername(String username) {
        Query query = entityManager.createNamedQuery("Client.CheckUsername");
          query.setParameter("username", username);
    return (Client) query.getSingleResult();
}

Query: @NamedQuery(name="Client.CheckUsername", query="SELECT c.username FROM Client c WHERE c.username = :username")

Service: 

@Autowired 
    ClientDAO clientDAO;

    public Client findClientByUsername(String username){
        System.out.println("findclientbyusername: " + username);
        return clientDAO.findByUsername(username);
    }

    public boolean isUsernameUnique(String username) {
        Client client = findClientByUsername(username);
        System.out.println("isusernameunique?: " + username);
        System.out.println(client);
        return (client == null || ((username != null) && client.getUsername() == username));

How can I fix this issue?

Upvotes: 2

Views: 4989

Answers (1)

Alican Balik
Alican Balik

Reputation: 1294

First of all you need to change your query because it is returning a string, not an object. findByUsername function returns object. 

@NamedQuery(name="Client.CheckUsername", query="SELECT c FROM Client c WHERE c.username = :username")

Service:

@Autowired 
ClientDAO clientDAO;

public Client findClientByUsername(String username){
      return clientDAO.findByUsername(username);
}

public boolean isUsernameUnique(String username) {
    Client client = findClientByUsername(username);
     return (client == null || ((username != null) && client.getUsername() == username));

dao: 

public Client findByUsername(String username) {
        Query query = entityManager.createNamedQuery("Client.CheckUsername");
          query.setParameter("username", username);
    return (Client) query.getSingleResult();
}

And I strongly recommend you to use DEBUG feature instead of printing variables out in the functions.

Upvotes: 3

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