android - Response handling with Volley -

i using volleyin project handling network requests. here sample json server returns

json object response

{"code":"success", "data":{"some data"}} 

json array response

{"code":"success", "data":["some data"]} 

when validation error or other error occurs, server returns following response:

{"code":"failed", "error":"access denied"} 

the problem parsing data. when request successful, in onresponse of responselistener, content of data key. as, expecting result same posted above. not getting why volley returning content of data , not complete json. had used volley earlier also. never faced such type of problem.

parsing code:

private void getonboardingcategories() {     response.listener<jsonarray> responselistener = new response.listener<jsonarray>() {          @override         public void onresponse(jsonarray response) {             log.d(log_tag, "category response: " + response.tostring());             if (response != null) {                 int datalength = response.length();                 (int = 0; < datalength; i++) {                     jsonobject jobject = response.optjsonobject(i);                     if (jobject != null) {                         categorytype2 categorytype2 = new categorytype2();                         categorytype2.set_id(jobject.optstring("_id"));                         categorytype2.setname(jobject.optstring("name"));                         categorytype2.setapp_icon_data(jobject.optstring("thumbnail_data"));                         categories.add(categorytype2);                     }                 }             }             if (isvisible())                 selladapter.notifydatasetchanged();         }     };      response.errorlistener errorlistener = new response.errorlistener() {          @override         public void onerrorresponse(volleyerror error) {             error.printstacktrace();             util.errorhandler(error, ctx);         }     };      jsonarrayrequest jsonobjectrequest = new jsonarrayrequest(method.get, url,             null, responselistener, errorlistener);     myapplication.getinstance().addtorequestqueue(jsonobjectrequest, "onboarding"); } 

response on success:

{    code: "success",    data: [              {                  _id: "55c06b05a3e0041a73cea744",                  name: "test category 1",                  thumbnail_data: "",              },              {                  _id: "55c06b16a3e0046108cea744",                  name: "test category 2",                  thumbnail_data: "",              }          ] } 

in onresponse of responselistener, data:

[     {         _id: "55c06b05a3e0041a73cea744",         name: "test category 1",         thumbnail_data: "",     },     {         _id: "55c06b16a3e0046108cea744",         name: "test category 2",         thumbnail_data: "",     } ] 

when error occurs, server returns response:

{"code":"failed", "error":"error_msg"} 

due this, volley throws parseexception expects jsonarray. need show error message user. earlier, using asynctask , handled error there. but, volley facing difficulty. looked volleyerror, didn't got clue.

update 1

private void getonboardingcategories() {     showspinnerdialog(true);     response.listener<jsonobject> responselistener = new response.listener<jsonobject>() {          @override         public void onresponse(jsonobject response) {             log.d(log_tag, "category response: " + response.tostring());             hidespinnerdialog();             string code = response.optstring("code");             if (code.equals("success")) {                 if (response != null) {                     jsonarray dataarray = response.optjsonarray("data");                     int datalength = dataarray.length();                     (int = 0; < datalength; i++) {                         jsonobject jobject = dataarray.optjsonobject(i);                         if (jobject != null) {                             categorytype2 categorytype2 = new categorytype2();                             categorytype2.set_id(jobject.optstring("_id"));                             categorytype2.setname(jobject.optstring("name"));                             categorytype2.setapp_icon_data(jobject.optstring("app_icon_data"));                             categories.add(categorytype2);                         }                     }                 }             }             if (isvisible())                 selladapter.notifydatasetchanged();         }     };      response.errorlistener errorlistener = new response.errorlistener() {          @override         public void onerrorresponse(volleyerror error) {             error.printstacktrace();             util.errorhandler(error, ctx);         }     };      jsonobjectrequest jsonobjectrequest = new jsonobjectrequest(method.get, url,             null, responselistener, errorlistener);     myapplication.getinstance().addtorequestqueue(jsonobjectrequest, "onboarding"); } 

update issue not volley. there issue on server end wrt gzip compression. going vote closing question.

but, when error occurs, parse exception, when making request jsonarray

use jsonobject. has() , jsonobject. isnull() check key present in json response before parsing json.

for example:

jsonobject jsonobject=new jsonobject(<server_response_string>);   if(jsonobject.has("data") && !jsonobject.isnull("data"))   {     // data jsonarray response   }else{      // message using error key    }