java - IllegalStateException when persisting an object -

public void lagremelding(string bruker, string msg) {         entitymanager em = emf.createentitymanager();         melding melding = new melding(bruker, msg);     try {         em.gettransaction().begin();         em.persist(melding);         em.gettransaction().commit();         em.close();     } catch (rollbackexception e) {         em.gettransaction().rollback();     } } 

the error report following:

java.lang.illegalstateexception:  exception description: cannot use entitytransaction while using jta.     org.eclipse.persistence.internal.jpa.transaction.jtatransactionwrapper.gettransaction(jtatransactionwrapper.java:73)     org.eclipse.persistence.internal.jpa.entitymanagerimpl.gettransaction(entitymanagerimpl.java:1311)     no.hib.dat104.oblig1.kontroll.lagremelding(kontroll.java:37)     no.hib.dat104.oblig1.meldingservlet.dopost(meldingservlet.java:80)     javax.servlet.http.httpservlet.service(httpservlet.java:646)     javax.servlet.http.httpservlet.service(httpservlet.java:727)     org.apache.tomcat.websocket.server.wsfilter.dofilter(wsfilter.java:52) 

all other examples of problem had been solved removing

em.gettransaction().begin(); 

and

em.gettransaction().commit(); 

but upon doing database doesn't update. care explain missing? pre-thanks taking time simple question :)

you can't begin , commit transaction way when using jta, try this:

public void lagremelding(string bruker, string msg) {         entitymanager em = emf.createentitymanager();         melding melding = new melding(bruker, msg);          usertransaction transaction = (usertransaction)new initialcontext().lookup("java:comp/usertransaction");      try {         transaction.begin();         em.persist(melding);         transaction.commit();         em.close();     } catch (rollbackexception e) {         transaction.rollback();     } }