Why em.persist() has no effect on database table? - jpa

Question

I have a RESTful service called AuthenticationEndpoint, which checks the users username/password pairs, creates token, save token to database and returns token to application client.
Code works without errors and exceptions.
UserEJB bean should save token to Token database table and AuthenticationEJB bean should update token field in User database table. But as I see in MySQL Workbench nothing is saved or updated.
UserEJB.getUsers() method work fine and return list of users and it seems that EJB container found persistence-unit ForthDynamicWebProject, but why I can't save and update entities? Thanks for your attention.
AuthenticationEndpoint RESTful service
#ApplicationScoped
#Path("/authentication")
public class AuthenticationEndpoint {
#Inject
AuthenticateEJB authenticateEJB;
#POST
#Produces(MediaType.APPLICATION_JSON)
#Consumes(MediaType.APPLICATION_JSON)
public Response authenticateUser(String jsonString) {
Gson gson = new Gson();
Credentials credentials = gson.fromJson(jsonString, Credentials.class);
String userName = credentials.getUserName();
String password = credentials.getPassword();
try {
User user = authenticateEJB.checkUser(userName, password);
if ((user instanceof User) && user != null) {
return Response.ok().header("token", user.getToken().getToken()).build();
} else {
return Response.status(Response.Status.FORBIDDEN).build();
}
} catch (Exception e) {
return Response.status(Response.Status.FORBIDDEN).build();
}
}
}
Here is the code of EJBs:
AuthenticateEJB
#LocalBean
#Stateless
public class AuthenticateEJB {
#PersistenceContext(unitName = "ForthDynamicWebProject")
EntityManager em;
#Inject
UserEJB userEJB;
public User checkUser(String userName, String password) {
List<User> users = userEJB.getUsers();
for (User user : users) {
if (user.getUsername().equals(userName) && user.getPassword().equals(password)) {
user.setToken(userEJB.updateToken());
em.merge(user);
return user;
}
}
return null;
}
}
UserEJB
#LocalBean
#Stateless
public class UserEJB {
#PersistenceContext(unitName = "ForthDynamicWebProject")
EntityManager em;
#Inject
Token token;
public List<User> getUsers() {
Query query = em.createQuery("from User");
return (List<User>) query.getResultList();
}
public Token updateToken() {
em.persist(token);
return token;
}
}
persistence.xml:
<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence
http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
<persistence-unit name="ForthDynamicWebProject" transaction-type="JTA">
<provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
<jta-data-source>jdbc/second_attempt_hibernate</jta-data-source>
<class>converters.ConverterLocalDateTime</class>
<class>entity.DocStatus</class>
<class>entity.DocType</class>
<class>entity.Document</class>
<class>entity.Employee</class>
<class>entity.MailOrder</class>
<class>entity.MailOrderStatus</class>
<class>entity.Token</class>
<class>entity.User</class>
</persistence-unit>
</persistence>
UPDATE:
Token entity
#Entity
#Table(name = "tokens")
#NamedQuery(name = "Token.findAll", query = "SELECT t FROM Token t")
public class Token implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private int id;
#Temporal(TemporalType.TIMESTAMP)
private Date loginTime;
private String token;
// bi-directional one-to-one association to User
#OneToOne(mappedBy = "token")
private User user;
public Token() {
ConverterLocalDateTime converter = new ConverterLocalDateTime();
loginTime = converter.convertToDatabaseColumn(LocalDateTime.now());
token = Double.toString(Math.random());
}
*getters and setters are not showed*
User entity
#Entity
#NamedQuery(name="User.findAll", query="SELECT u FROM User u")
public class User implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy=GenerationType.IDENTITY)
private int id;
private String password;
private String username;
//bi-directional one-to-one association to Employee
#OneToOne(mappedBy="user")
private Employee employee;
//bi-directional one-to-one association to Token
#OneToOne
#JoinColumn(name="tokID")
private Token token;
public User() {
}
*getters and setters are not showed*

Answer 1

Maybe I am missing something, but if your user ejb is meant to be bound to a single user, this is not the case, as a stateless can be reused for several other clients, and therefore the token will be reused along with the ooled instance. Check if this is the correct behavior.
Second, you cannot inject the tokens JPA entity or at least not with the current code, the variable would always be null. Maybe this is the reason you are not seeing it persisted.
Third, there are other things I would change, but it's another different question.