java - org.json.JSONObject cannot be converted to JSONArray -

i unable display values coming in form of json response

and failed convert these values , display textview..

my json reponse :

{"calculate":{"persons":"148429","cost":25232.93}} 

and main activity java file :

import android.app.progressdialog; import android.os.asynctask; import android.support.v7.app.actionbaractivity; import android.os.bundle; import android.view.menu; import android.view.menuitem; import android.view.view; import android.widget.button; import android.widget.textview;  import org.json.jsonarray; import org.json.jsonexception; import org.json.jsonobject;   public class mainactivity extends actionbaractivity {     textview uid;     textview name1;     textview email1;     button btngetdata;     //url json array     private static string url = "http://urls.p/getdata.php?";     //json node names     private static final string tag_user = "calculate";     //private static final string tag_id = "id";     private static final string tag_name = "persons";     private static final string tag_email = "cost";     jsonarray user = null;     @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.activity_main);         btngetdata = (button)findviewbyid(r.id.getdata);         btngetdata.setonclicklistener(new view.onclicklistener() {             @override             public void onclick(view view) {                 new jsonparse().execute();             }         });     }     private class jsonparse extends asynctask<string, string, jsonobject> {         private progressdialog pdialog;         @override         protected void onpreexecute() {             super.onpreexecute();             uid = (textview)findviewbyid(r.id.uid);             name1 = (textview)findviewbyid(r.id.name);             email1 = (textview)findviewbyid(r.id.email);             pdialog = new progressdialog(mainactivity.this);             pdialog.setmessage("getting data ...");             pdialog.setindeterminate(false);             pdialog.setcancelable(true);             pdialog.show();         }         @override         protected jsonobject doinbackground(string... args) {             jsonparser jparser = new jsonparser();             // getting json url             jsonobject json = jparser.getjsonfromurl(url);             return json;         }         @override         protected void onpostexecute(jsonobject json) {             pdialog.dismiss();              (int = 0; < json.length(); i++) {                 try {                     //jsonobject c = json.getjsonobject(i);                     // getting json array                     jsonobject c = user.getjsonobject(i);                     // storing  json item in variable                     // string id = c.getstring(tag_id);                     //system.out.println();                     string name = c.getstring(tag_name);                     // system.out.println(name);                     string email = c.getstring(tag_email);                     //system.out.println(email);                     //set json data in textview                     //uid.settext(id);                     name1.settext(name);                     email1.settext(email);                 } catch (jsonexception e) {                     e.printstacktrace();                 }             }         }     } } 

and json parser class:

import android.util.log;  import org.apache.http.httpentity; import org.apache.http.httpresponse; import org.apache.http.client.clientprotocolexception; import org.apache.http.client.methods.httppost; import org.apache.http.impl.client.defaulthttpclient; import org.json.jsonexception; import org.json.jsonobject;  import java.io.bufferedreader; import java.io.ioexception; import java.io.inputstream; import java.io.inputstreamreader; import java.io.unsupportedencodingexception;  /**  * created admin on 09-04-2015.  */ public class jsonparser {     static inputstream = null;     static jsonobject jobj = null;     static string json = "";     // constructor     public jsonparser() {     }     public jsonobject getjsonfromurl(string url) {         // making http request         try {             // defaulthttpclient             defaulthttpclient httpclient = new defaulthttpclient();             httppost httppost = new httppost(url);             httpresponse httpresponse = httpclient.execute(httppost);             httpentity httpentity = httpresponse.getentity();             = httpentity.getcontent();         } catch (unsupportedencodingexception e) {             e.printstacktrace();         } catch (clientprotocolexception e) {             e.printstacktrace();         } catch (ioexception e) {             e.printstacktrace();         }         try {             bufferedreader reader = new bufferedreader(new inputstreamreader(                     is, "iso-8859-1"), 8);             stringbuilder sb = new stringbuilder();             string line = null;             while ((line = reader.readline()) != null) {                 sb.append(line + "n");             }             is.close();             json = sb.tostring();         } catch (exception e) {             log.e("buffer error", "error converting result " + e.tostring());         }         // try parse string json object         try {             jobj = new jsonobject(json);         } catch (jsonexception e) {             log.e("json parser", "error parsing data " + e.tostring());         }         // return json string         return jobj;     } } 

activity_main.xml file

<linearlayout xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:tools="http://schemas.android.com/tools"     android:layout_width="match_parent"     android:orientation="vertical"     android:layout_height="match_parent"     android:paddingbottom="@dimen/activity_vertical_margin"     android:paddingleft="@dimen/activity_horizontal_margin"     android:paddingright="@dimen/activity_horizontal_margin"     android:paddingtop="@dimen/activity_vertical_margin"     tools:context=".mainactivity" >     <textview         android:id="@+id/name"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_below="@+id/uid"         android:textappearance="?android:attr/textappearancelarge"         android:textcolor="#ff000000" />     <textview         android:id="@+id/email"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_below="@+id/name"         android:textappearance="?android:attr/textappearancelarge"         android:layout_alignright="@+id/getdata"         android:layout_alignend="@+id/getdata"         android:textcolor="#ff000000" />     <textview         android:id="@+id/uid"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:textappearance="?android:attr/textappearancelarge"         android:layout_alignparentright="true"         android:layout_alignparentend="true"         android:layout_alignparenttop="true"         android:textcolor="#ff000000"  />      <button         android:id="@+id/getdata"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_alignparentbottom="true"         android:layout_centerhorizontal="true"         android:layout_marginbottom="23dp"         android:text="get data"         android:layout_gravity="center_horizontal" />  </linearlayout> 

and logcat:

04-09 09:04:34.904    1170-1170/com.example.health.myapplication w/system.err﹕ org.json.jsonexception: value {"cost":25232.93,"persons":"148429"} @ calculate of type org.json.jsonobject cannot converted jsonarray 

your json jsonobject not jsonarray.

{ represents jsonobject node

[ represents jsonarray node

so having for (int = 0; < json.length(); i++) { wrong

in onpostexecute

jsonobject calculate = json.optjsonobject("calculate"); string person = calculate.optstring("persons"); string cost = calculate.optstring("cost");