android - Realm - Migration error -

error: realm on disc newer 1 specified: v1 vs. v0

i have tried add migration code project. see following error not sure how resolve it. noticed documentation needs updated realmmigration. don't want delete data, need keep stored. may not setting right trying follow documentation me bit confusing migration. here code:

    visnetawrap.realmconfiguration = new realmconfiguration.builder(this).build();      realm.setdefaultconfiguration(visnetawrap.realmconfiguration);      try {         realm temprealmthread = realm.getdefaultinstance();         temprealmthread.close();     }     catch (realmmigrationneededexception e) {         realm.migraterealm(visnetawrap.realmconfiguration, new realmmigration() {             @override             public long execute(realm realm, long l) {                 return 1;             }         });         realm.setdefaultconfiguration(visnetawrap.realmconfiguration);         log.d("realmmigration", "schema has been upgraded.");     } 

you need reflect changes in migration. check example, hope helps.