java - Android, how to initiate realm in AsyncTask? -

i have asynctask in application below. have fetch data realm(which stored in activity) asynctask. below asynctask code:

public class makeasyncrequest extends asynctask<object, string, makeasyncrequest.responsedatatype>{  public context asynccontext;     private makeasyncrequest(context context){         asynccontext = context;     }  private static final okhttpclient client = new okhttpclient(); private static final mediatype json = mediatype.parse("application/json; charset=utf-8");  private makerequest.responsehandler handler; private string method; private user user; private realm realm;   class responsedatatype {     inputstream inputstream;     string string;     string cookie; } makeasyncrequest(makerequest.responsehandler responsehandler, string type) {     method = type;     handler = responsehandler; }   @override  protected responsedatatype doinbackground(object... params) {     try {         requests requests = new requests((context) params[0]);         string url = params[1].tostring();         string bodyjson = null;         if(method.equals("put") || method.equals("post")) {             bodyjson = params[2].tostring();         }         final request.builder builder;         response response;         requestbody body;         switch (method) {              case "get": builder = new request.builder().url(url);                 break;              case "download": builder = new request.builder().url(url);                 break;              case "post": body = requestbody.create(json, bodyjson);                 builder = new request.builder()                         .url(url)                         .post(body)                         .addheader("cookie", "key=value");                 break;              case "put":  body = requestbody.create(json, bodyjson);                 builder = new request.builder()                         .url(url)                         .put(body);                 break;              default: builder = new request.builder().url(url);         }         builder.addheader("accept", "application/json");         realm = realmcontroller.initialize(this).getrealm();         final realmresults<user> users = realm.where(user.class).findallasync();         user = users.first();         if(user.getcookie() !== null && !user.getcookie().isempty()){             builder.addheader("cookie", "user.getcookie()");         }         response = client.newcall(builder.build()).execute();         responsedatatype responsedatatype = new responsedatatype();         if(method.equals("download")) { responsedatatype.inputstream = response.body().bytestream(); }         else {             responsedatatype.string = response.body().string();             responsedatatype.cookie = response.headers().get("set-cookie");             cookiemanager cmanager = new cookiemanager(null, cookiepolicy.accept_all);             cmanager.getcookiestore().getcookies();         }         return  responsedatatype;      } catch (ioexception e) {         return null;     } }  @override protected void onpostexecute(responsedatatype response) {     try {         if (method.equals("download")) {             handler.onfinishcallback(response.inputstream);         }else {             handler.onfinishcallback(response.string, response.cookie);             cookiemanager cmanager = new cookiemanager(null, cookiepolicy.accept_all);             cmanager.getcookiestore().getcookies();         }     }catch (exception e){         log.d("hexceptionerror", e.tostring());         handler.onfinishcallback("{\n" +                 "  \"error\": \"error\"\n" +                 "}","");     } } 

i received access error - "realm access incorrect thread. realm objects can accessed on thread created." whenever control tries execute realm results or first object realm.

below realmcontroller created control realm instance:

public class realmcontroller {`public static realmcontroller initialize(activity activity) {      if (instance == null) {         instance = new realmcontroller(activity.getapplication());     }     return instance; } public static realmcontroller initialize(makeasyncrequest activity) {      if (instance == null) {         instance = new realmcontroller(activity.);     }     return instance; } }` 

i have user model(realm object) setters , getters.

the point - cannot create , access realm on different threads, i.e. create realm instance in activity , use in .doinbackground() method. create , release realm before , after transaction. there may issue - don't register quer observer on background thread in asynctask - doesn't have looper initialized - use main thread or handlerthread. release realm after no longer needed (you didn't in code), because realm has limited number of instances.