CODEWITHSUNDEEP
javajbosswildflyentitymanagerpersistence-unit
Marcin
Marcin

Reputation: 21

WildFly/Jboss/persistance-unit/Entity Manager - How to create new connection every time when user calls GET API Endpoint

I'm trying to modify existing Java app (WildFly, Jboss, oracle) which currently working fine as using persistence-unit and EntityManager connect to Oracle database(using standalone.xml and persistence.xml). However, I need to create every time new connection to database for the user which calls new GET API Endpoint using credentials from the HttpHeaders. Currently, I'm creating new entitymanager object which session is commit, rollback nad close. Unfortunately time response for every call become higher and higher. There is warning about "PersistenceUnitUser" being already registered and memory usage constantly growing. So that is bad solution.

Is there any proper way to do it, which works witout any harms ?

P.S. Currently app using standalone.xml and persistence.xml. And that is working fine. I'm calling java api endpoint using entity manager being connected as Admin user/pass but I need to create new connection using user/pass from the httpHeaders and call one sql statement to see proper results as ORACLE uses reserved word such us: 'user'. For instance : select * from table where create_usr = user. When done 'Main EntityManager will use data from it to continue some process.

Please see code example below :


@GET
  @Path("/todo-list-enriched")
  @Produces(MediaType.APPLICATION_JSON)
  public Response getToDoListEnriched(@Context HttpHeaders httpHeaders, @QueryParam("skip") int elementNumber, @QueryParam("take") int pageSize, @QueryParam("orderby") String orderBy) 
{
    String userName = httpHeaders.getHeaderString(X_USER_NAME);
    String userName = httpHeaders.getHeaderString(X_PASSWORD);


EntityManager entityManager = null;

try {


Map<String, String> persistenceMap = new HashMap<String, String>();

persistenceMap.put("hibernate.dialect","org.hibernate.dialect.Oracle8iDialect");
persistenceMap.put("hibernate.connection.username", asUserName);
persistenceMap.put("hibernate.connection.password", asPassword);

EntityManagerFactory emf = Persistence.createEntityManagerFactory("PersistenceUnitUser", persistenceMap);

entityManager = emf.createEntityManager();

if (!entityManager.getTransaction().isActive()) {
   entityManager.getTransaction().begin();
}

-- Do some works as select, update, select 
-- and after that 

if (entityManager.getTransaction().isActive()) {
     entityManager.getTransaction().commit();
 }
}
catch (Exception ex)
{
 if (entityManager != null && entityManager.getTransaction().isActive()) {
  entityManager.getTransaction().rollback();
 }
}
finally {
  if (entityManager != null && entityManager.isOpen()) {
   entityManager.close();
 }
}

}
}

``

Best Regards
Marcin

Upvotes: 0

Views: 411

Answers (1)

ehsavoie
ehsavoie

Reputation: 3517

You should define a connection pool and a datasource in the standalone.xml (cf. https://docs.wildfly.org/26.1/Admin_Guide.html#DataSource) and then use it in your persistence.xml and inject the EntitytManager in your rest service class (cf. https://docs.wildfly.org/26.1/Developer_Guide.html#entity-manager). You may look at this example application: https://github.com/wildfly/quickstart/tree/main/todo-backend

Upvotes: 0

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