php - display data from mysql using json to listview in fragment -

i trying load data database using json , display in listview in fragment. have 2 classes, 1 called downloader , 1 called perser. add data listview in fragmnet.

how can achieve because work fine in content_mani want fragment

import android.app.progressdialog; import android.content.context; import android.os.asynctask; import android.widget.listview; import android.widget.toast;  import java.io.bufferedinputstream; import java.io.bufferedreader; import java.io.ioexception; import java.io.inputstream; import java.io.inputstreamreader; import java.net.httpurlconnection; import java.net.malformedurlexception; import java.net.url;  import info.androidhive.materialtabs.fragments.onefragment;  /**  * created george on 25/06/2016.  */ public class downloader extends asynctask<void ,integer,string>{     context c;     string urladdress;     listview lv;     progressdialog progressdialog;      public downloader(mainactivity context, listview listview, string urladdress) {         this.c = context;         this.urladdress = urladdress;         this.lv = listview;     } // before job start     @override     protected void onpreexecute() {         super.onpreexecute();         progressdialog=new progressdialog(c);         progressdialog.settitle("fetch data");         progressdialog.setmessage("fetching data.....please wait");         progressdialog.show();     }      @override     protected string doinbackground(void... params) {         string data=downloaddata();         return data;     }      @override     protected void onprogressupdate(integer... values) {         super.onprogressupdate(values);     }      @override     protected void onpostexecute(string s) {         super.onpostexecute(s);         progressdialog.dismiss();         if(s!=null){     parser p=new parser(c,s,lv);            p.execute();          }else {             toast.maketext(c,"unable download data",toast.length_long).show();          }     }     private string downloaddata(){         inputstream inputstream=null;         string line=null;         try{             url url=new url(urladdress);             httpurlconnection httpurlconnection=(httpurlconnection) url.openconnection();             inputstream=new bufferedinputstream(httpurlconnection.getinputstream());             bufferedreader bufferedreader=new bufferedreader(new inputstreamreader(inputstream));             stringbuffer stringbuffer=new stringbuffer();             if (bufferedreader!=null)             {                 while ((line=bufferedreader.readline())!=null)                 {                     stringbuffer.append(line+"\n");                  }             }else             {                 return null;             }             return  stringbuffer.tostring();         } catch (malformedurlexception e) {             e.printstacktrace();         }         catch (ioexception e) {             e.printstacktrace();         }       {             if (inputstream!=null)             {                 try {                     inputstream.close();                 } catch (ioexception e) {                     e.printstacktrace();                 }             }         }         return  null;     } }  ,    package info.androidhive.materialtabs.activity;   import android.app.*; import android.content.context; import android.os.asynctask; import android.widget.*; import info.androidhive.materialtabs.r;  import org.json.jsonarray; import org.json.jsonexception; import org.json.jsonobject;  import java.util.*;   public class parser extends asynctask<void,integer,integer> {     context c;     listview lv;     string data;     arraylist<string> users=new arraylist<>();     progressdialog pd;      public parser(context c, string data, listview lv) {         this.c = c;         this.data = data;         this.lv = lv;     }      @override     protected void onpreexecute() {         super.onpreexecute();         pd=new progressdialog(c);         pd.settitle("parser");         pd.setmessage("parsing....please wait");         pd.show();     }      @override     protected integer doinbackground(void... params) {         return  this.perse();      }      @override     protected void onpostexecute(integer integer) {         super.onpostexecute(integer);          if(integer==1){   arrayadapter<string> adapter=new arrayadapter<string>(c, android.r.layout.simple_list_item_1,users);             lv.setadapter(adapter);         }         else {             toast.maketext(c,"unable perse",toast.length_long).show();         }         pd.dismiss();     } private  int perse(){     try{         jsonarray ja=new jsonarray(data);         jsonobject jo=null;         users.clear();         (int i=0;i<ja.length();i++){             jo=ja.getjsonobject(i);             string name=jo.getstring("category_name");             string id=jo.getstring("idcategories");             users.add(name);         }          return 1;      } catch (jsonexception e) {         e.printstacktrace();     }     return 0; }  }      package info.androidhive.materialtabs.fragments;  import android.os.bundle; import android.support.v4.app.fragment; import android.view.layoutinflater; import android.view.view; import android.view.viewgroup; import android.widget.button; import android.widget.listview;  import info.androidhive.materialtabs.r; import info.androidhive.materialtabs.activity.downloader;   public class onefragment extends fragment{     button btn_categories;     string urladdress="http://192.168.0.107/android/users.php";      @override     public void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);     }      @override     public view oncreateview(layoutinflater inflater, viewgroup container,                              bundle savedinstancestate) {         // inflate layout fragment       view  view =inflater.inflate(r.layout.fragment_one, container, false);         btn_categories = (button) view.findviewbyid(r.id.btn_categories);         final listview lv = (listview) view.findviewbyid(r.id.lv);         //final downloader downloader=new downloader(this, lv, urladdress);         //downloader.execute();          return view;     }  } 

i assume can correctly retrieve json file server. following code did app.

class loaddataasyn extends asynctask<void,void,void>{     jsonarray data;     @override     protected void onpreexecute() {         super.onpreexecute();         // can use progressdialog indicate request start;     }      @override     protected void doinbackground(void... params) {         //user custom class , contactlist return jsonarray         data = new user().contactlist();         return null;     }      @override     protected void onpostexecute(void avoid) {         super.onpostexecute(avoid);         if (data!=null){             if (adapter==null){                 adapter = new customadapter(context.this,data);                 listview.setadapter(adapter);             }else{                 adapter.refresh(data);             }         }     } } 

the idea had in code directly pass json array adapter in custom class:

public class customeradapter extends baseadapter { context context; jsonarray data; public searchschooladapter (context context,jsonarray data){     this.context= context;     this.data = data; } @override public int getcount() {     if (data!=null){         return data.length();     }     return 0; }  @override public object getitem(int position) {     return position; }  @override public long getitemid(int position) {     return position; }  @override public view getview(int position, view convertview, viewgroup parent) {     oneholder holder;     if (convertview == null||!(convertview.gettag() instanceof oneholder)){         convertview = layoutinflater.from(context).inflate(r.layout.listrow_layout,null);         holder = new oneholder();         holder.image = (imageview)convertview.findviewbyid(r.id.pic);         holder.full =(textview)convertview.findviewbyid(r.id.fullname);         convertview.settag(holder);     }else{         holder = (oneholder)convertview.gettag();     }     if (data!=null&&data.length()>position){         try {             jsonobject 1 = data.getjsonobject(position);             holder.full.settext(one.getstring("name"));         } catch (jsonexception e) {             e.printstacktrace();         }      }     return convertview; } class oneholder {     imageview image;     textview full,abb; } public void refersh(jsonarray data){     this.data=data;     notifydatasetchanged(); } 

} not know if asking, hope can you.