android - realmio - realm objects can only be accessed from thread they were created -

question sound similar asked questions. have referred couldn't find solution problem i'm having.

private addcartitemdialog.cartitemlistener cartitemlistener = new addcartitemdialog.cartitemlistener() {         @override         public void onokclick(product cartitem, int quantity) {              realm.executetransactionasync(new realm.transaction() {                 @override                 public void execute(realm bgrealm) {                      draftinvoice draftinvoice = bgrealm.where(draftinvoice.class).equalto("shop.id", shopid).findfirst();                       invoiceitem invoiceitem = bgrealm.createobject(invoiceitem.class);                     invoiceitem.setprice(cartitem.getprice());                     invoiceitem.setid(cartitem.getid());                     invoiceitem.setquantity(quantity);                     invoiceitem.calculatetotal();                      draftinvoice.getinvoiceitems().add(invoiceitem);                      updatecartitemcount(draftinvoice.getinvoiceitems().size());                 }             }, () -> {              }, error -> {                 error.printstacktrace();                 logger.e(error.getmessage());             });          }          @override         public void oncancelclick() {          }     }; 

error log shows following error -

08-28 15:10:25.214 4996-4996/com.example.realshoptest w/system.err: java.lang.illegalstateexception: realm access incorrect thread. realm objects can accessed on thread created. 08-28 15:10:25.214 4996-4996/com.example.realshoptest w/system.err:     @ io.realm.baserealm.checkifvalid(baserealm.java:449) 08-28 15:10:25.214 4996-4996/com.example.realshoptest w/system.err:     @ io.realm.productrealmproxy.realmget$price(productrealmproxy.java:159) 08-28 15:10:25.214 4996-4996/com.example.realshoptest w/system.err:     @ com.example.realshoptest.models.product.getprice(product.java:75) 08-28 15:10:25.214 4996-4996/com.example.realshoptest w/system.err:     @ com.example.realshoptest.newinvoiceactivity$1$1.execute(newinvoiceactivity.java:76) 08-28 15:10:25.214 4996-4996/com.example.realshoptest w/system.err:     @ io.realm.realm$1.run(realm.java:1187) 08-28 15:10:25.214 4996-4996/com.example.realshoptest w/system.err:     @ io.realm.internal.async.bgpriorityrunnable.run(bgpriorityrunnable.java:34) 08-28 15:10:25.214 4996-4996/com.example.realshoptest w/system.err:     @ java.util.concurrent.executors$runnableadapter.call(executors.java:422) 08-28 15:10:25.214 4996-4996/com.example.realshoptest w/system.err:     @ java.util.concurrent.futuretask.run(futuretask.java:237) 08-28 15:10:25.214 4996-4996/com.example.realshoptest w/system.err:     @ java.util.concurrent.threadpoolexecutor.runworker(threadpoolexecutor.java:1112) 08-28 15:10:25.214 4996-4996/com.example.realshoptest w/system.err:     @ java.util.concurrent.threadpoolexecutor$worker.run(threadpoolexecutor.java:587) 08-28 15:10:25.214 4996-4996/com.example.realshoptest w/system.err:     @ java.lang.thread.run(thread.java:818) 08-28 15:10:25.214 4996-4996/com.example.realshoptest e/testshopapp: realm access incorrect thread. realm objects can accessed on thread created. 

error occurs @ line - invoiceitem.setprice(cartitem.getprice());

this piece of code seems work understanding not i'm accessing objects async'ly in same thread. missing here ?

public void onokclick(product cartitem, int quantity) { 

this line receives product ui thread's realm instance

        realm.executetransactionasync(new realm.transaction() {             @override             public void execute(realm bgrealm) { 

this call creates realm instance background thread

                invoiceitem.setprice(cartitem.getprice()); 

cartitem still belongs ui thread's realm instance, therefore cannot accessed on background thread

two solutions:

1.) send parameters background thread

    public void onokclick(product cartitem, int quantity) {         final long cartitemid = cartitem.getid();         final string price = cartitem.getprice();         realm.executetransactionasync(new realm.transaction() {             @override             public void execute(realm bgrealm) {                 draftinvoice draftinvoice = bgrealm.where(draftinvoice.class).equalto("shop.id", shopid).findfirst();                 invoiceitem invoiceitem = bgrealm.createobject(invoiceitem.class);                 invoiceitem.setprice(price);                 invoiceitem.setid(cartitemid); 

or

2.) requery object background thread's realm instance

    public void onokclick(product cartitem, int quantity) {         final long cartitemid = cartitem.getid();         realm.executetransactionasync(new realm.transaction() {             @override             public void execute(realm bgrealm) {                 product product = bgrealm.where(product.class).equalto("id", cartitemid).findfirst();                 draftinvoice draftinvoice = bgrealm.where(draftinvoice.class).equalto("shop.id", shopid).findfirst();                 invoiceitem invoiceitem = bgrealm.createobject(invoiceitem.class);                 invoiceitem.setprice(product.getprice());                 invoiceitem.setid(cartitemid); 

the second solution cleaner.