php - E/AndroidRuntime: FATAL EXCEPTION: AsyncTask #1 java.lang.RuntimeException: An error occured while executing doInBackground() -

i beginner in programming , want create app display markers on map using coordinates database( hosted 000webhost), using php , json.the map working, there no markers. please me because cannot figure out.

this error message get:

e/androidruntime: fatal exception: asynctask #1                                                    process: com.kid.compaq.licenta, pid: 24949                                                    java.lang.runtimeexception: error occured while executing doinbackground()                                                        @ android.os.asynctask$3.done(asynctask.java:304)                                                        @ java.util.concurrent.futuretask.finishcompletion(futuretask.java:355)                                                        @ java.util.concurrent.futuretask.setexception(futuretask.java:222)                                                        @ java.util.concurrent.futuretask.run(futuretask.java:242)                                                        @ android.os.asynctask$serialexecutor$1.run(asynctask.java:231)                                                        @ java.util.concurrent.threadpoolexecutor.runworker(threadpoolexecutor.java:1112)                                                        @ java.util.concurrent.threadpoolexecutor$worker.run(threadpoolexecutor.java:587)                                                        @ java.lang.thread.run(thread.java:818)                                                     caused by: java.lang.illegalstateexception: not on main thread                                                        @ maps.f.g.b(unknown source)                                                        @ maps.z.d.a(unknown source)                                                        @ maps.ag.t.a(unknown source)                                                        @ uz.ontransact(:com.google.android.gms.dynamitemodulesb:167)                                                        @ android.os.binder.transact(binder.java:385)                                                        @ com.google.android.gms.maps.internal.igooglemapdelegate$zza$zza.addmarker(unknown source)                                                        @ com.google.android.gms.maps.googlemap.addmarker(unknown source)                                                        @ com.kid.compaq.licenta.mapsactivity$markertask.doinbackground(mapsactivity.java:106)                                                        @ com.kid.compaq.licenta.mapsactivity$markertask.doinbackground(mapsactivity.java:62)                                                        @ android.os.asynctask$2.call(asynctask.java:292)                                                        @ java.util.concurrent.futuretask.run(futuretask.java:237)                                                        @ android.os.asynctask$serialexecutor$1.run(asynctask.java:231)                                                         @ java.util.concurrent.threadpoolexecutor.runworker(threadpoolexecutor.java:1112)                                                         @ java.util.concurrent.threadpoolexecutor$worker.run(threadpoolexecutor.java:587)                                                         @ java.lang.thread.run(thread.java:818)  05-28 19:22:28.324 731-919/? e/inputdispatcher: channel 'd1579c5 com.kid.compaq.licenta/com.kid.compaq.licenta.mapsactivity (server)' ~ channel unrecoverably broken , disposed! 05-28 19:23:01.289 731-1342/? e/sensors: handletodriver handle(0) 05-28 19:23:01.290 731-1342/? e/sensors: handletodriver handle(0) 05-28 19:23:01.290 731-1342/? e/sensors: new setdelay handle(0),ns(20000000)m, error(0), index(2) 05-28 19:23:01.299 731-939/? e/wifistatemachine:  disconnectedstate (when=0 what=131143 arg1=10009 arg2=682) cmd_start_scan 10009 682 ic=0 proc(ms):0 dur:692 cnt=2252 rssi=-64 f=-1 sc=0 link=-1 tx=0,0, 0,0, 0,0  rx=0,0 fiv=20000 [on:0 tx:0 rx:0 period:121028] screen [on:0 period:-131266637] 05-28 19:23:01.299 731-939/? e/wifistatemachine:  connectmodestate (when=-1ms what=131143 arg1=10009 arg2=682) cmd_start_scan 10009 682 ic=0 proc(ms):1 dur:692 cnt=2252 rssi=-64 f=-1 sc=0 link=-1 tx=0,0, 0,0, 0,0  rx=0,0 fiv=20000 [on:0 tx:0 rx:0 period:0] screen [on:0 period:-131266637] 05-28 19:23:01.300 731-939/? e/wifistatemachine:  driverstartedstate (when=-2ms what=131143 arg1=10009 arg2=682) cmd_start_scan 10009 682 ic=0 proc(ms):2 dur:692 cnt=2252 rssi=-64 f=-1 sc=0 link=-1 tx=0,0, 0,0, 0,0  rx=0,0 fiv=20000 [on:0 tx:0 rx:0 period:1] screen [on:0 period:-131266636] 05-28 19:23:01.300 731-939/? e/wifistatemachine: stopreconnectwifi wfd=false stopscan=false mdontreconnectandscan=false 05-28 19:23:01.302 731-939/? e/wifistatemachine: [1.464.452.581.302 ms] notescanstartworksource{10009} uid 10009 05-28 19:23:01.304 731-10206/? e/wifimonitor: handleevent unknown: 15  ctrl-event-scan-started  05-28 19:23:01.322 1716-1792/? e/celllocation: create gsmcelllocation 05-28 19:23:01.358 1716-1792/? e/celllocation: create gsmcelllocation 05-28 19:23:01.415 1716-25019/? e/mplugin: unsupported class: com.mediatek.common.telephony.ionlyownersimsupport 

mapsactivity:

import android.os.asynctask; import android.os.bundle; import android.support.v4.app.fragmentactivity; import android.util.log;  import com.google.android.gms.maps.googlemap; import com.google.android.gms.maps.onmapreadycallback; import com.google.android.gms.maps.supportmapfragment; import com.google.android.gms.maps.model.bitmapdescriptorfactory; import com.google.android.gms.maps.model.latlng; import com.google.android.gms.maps.model.markeroptions;  import org.json.jsonarray; import org.json.jsonexception; import org.json.jsonobject;  import java.io.bufferedreader; import java.io.inputstream; import java.io.inputstreamreader; import java.net.httpurlconnection; import java.net.url;  public class mapsactivity extends fragmentactivity implements onmapreadycallback {      httpurlconnection urlconnection= null;     private googlemap mmap;      @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.activity_maps);         // obtain supportmapfragment , notified when map ready used.         supportmapfragment mapfragment = (supportmapfragment) getsupportfragmentmanager()                 .findfragmentbyid(r.id.map);         mapfragment.getmapasync(this);         new markertask().execute();     }       /**      * manipulates map once available.      * callback triggered when map ready used.      * can add markers or lines, add listeners or move camera. in case,      * add marker near sydney, australia.      * if google play services not installed on device, user prompted install      * inside supportmapfragment. method triggered once user has      * installed google play services , returned app.      */     @override     public void onmapready(googlemap googlemap) {         mmap = googlemap;         mmap.getuisettings().iscompassenabled();         mmap.getuisettings().setzoomcontrolsenabled(true);         mmap.getuisettings().setscrollgesturesenabled(true);         mmap.getuisettings().setmaptoolbarenabled(true);       }      class markertask extends asynctask<void, string, void> {            @override         protected void onpreexecute() {             super.onpreexecute();         }          @override         protected void doinbackground(void... params) {              inputstream = null;             string result="";             try {                 url url = new url("http://catcat.netne.net/get_mark.php");                 urlconnection = (httpurlconnection) url.openconnection();                 urlconnection.connect();                 = urlconnection.getinputstream(); //2 sec, tel             } catch (exception e) {                 log.e("url connection", e.tostring());             }             try{                 bufferedreader reader = new bufferedreader(new inputstreamreader(is,"utf-8"));                 string line= null;                 while( (line= reader.readline())!=null){                     result +=line;                 }                 is.close();             }             catch (exception e){                 e.printstacktrace();             }             try{                 jsonarray jsonarray = new jsonarray(result);                 (int = 0; < jsonarray.length(); i++) {                     jsonobject jsonobj = jsonarray.getjsonobject(i);                      latlng latlng = new latlng(jsonobj.getjsonarray("latlng").getdouble(0),                             jsonobj.getjsonarray("latlng").getdouble(1));                       // create marker each station in json data.                     mmap.addmarker(new markeroptions()                             .icon(bitmapdescriptorfactory.defaultmarker(bitmapdescriptorfactory.hue_blue))                             .title(jsonobj.getstring("nume"))                             .position(latlng));                 }             } catch (jsonexception e) {                 e.printstacktrace();             }               return null;          }             // executed after complete execution of doinbackground() method             @override             protected void onpostexecute (void result){               }      } } 

php file:

<?php    @$dbhandle = mysql_connect($host,$user,$pass)or die("unable connect mysql");  $selected = mysql_select_db($db,$dbhandle)or die("could not select licenta");       $sql="select id_st, nume, concat_ws(\",\",lat, lng) latlng statii";     $result = mysql_query($sql);     $response= array();     while($row= mysql_fetch_assoc($result)){          $response[]=array(                             'nume'          => $row['nume'],                             'latlng'        => explode(',', $row['latlng']),                             'id_st'         => $row['id_st']                             );     }  //$bd_json = json_encode($response); echo json_encode($response); exit();  ?> 

json response:

[{     "nume": "merge in sfarsit",     "latlng": ["45.659721", "25.606859"],     "id_st": "5" }, {     "nume": "memo cantina",     "latlng": ["45.655075", "25.581560"],     "id_st": "6" }] 

one issue see in code below adding marker google map (on ui thread) background thread:

// create marker each station in json data.                 mmap.addmarker(new markeroptions()                         .icon(bitmapdescriptorfactory.defaultmarker(bitmapdescriptorfactory.hue_blue))                         .title(jsonobj.getstring("nume"))                         .position(latlng)); 

either create entire set of markers built in loop first, maybe in list, , pass list onpostexecute @ end add them map there, or post each marker using onprogressupdate method like:

// create marker each station in json data. mmarker = new markeroptions().icon(bitmapdescriptorfactory.defaultmarker(bitmapdescriptorfactory.hue_blue))                         .title(jsonobj.getstring("nume"))                         .position(latlng); onprogressupdate(mmarker); 

make sure add:

markeroptions mmarker; 

below line:

private googlemap mmap; 

and override onprogressupdate method:

protected void onprogressupdate(markeroptions marker) {      mmap.addmarker(marker);  } 

don't forget change

class markertask extends asynctask<void, string, void> { 

to

class markertask extends asynctask<void, markeroptions, void> { 

while might past issue, should review asynctask class , familiar it.

good luck!