android - Fatal Exception AsyncTask doInBackground -

android - Fatal Exception AsyncTask doInBackground -

this main activity code when run code says unfortunately programme has stopped working .. in logcatit says: error occurred executing doinbackground()..

please help asap.

and echoed recieved json values , fetched , added array list.. guys it's frustrating not beingness able figure out please again

import java.util.arraylist; import java.util.hashmap; import java.util.list; import org.apache.http.namevaluepair; import org.apache.http.message.basicnamevaluepair; import org.json.jsonarray; import org.json.jsonexception; import org.json.jsonobject; import android.app.activity; import android.app.fragment; import android.app.progressdialog; import android.content.context; import android.os.asynctask; import android.os.bundle; import android.support.v4.util.arraymap; import android.util.log; import android.view.layoutinflater; import android.view.menu; import android.view.menuitem; import android.view.view; import android.view.viewgroup; import android.widget.adapterview; import android.widget.adapterview.onitemclicklistener; import android.widget.listview; import android.widget.toast; public class mainactivity extends activity { private static final string url="http://10.0.3.2/other"; static string title = "username"; static string desciption = "password"; @override protected void oncreate(bundle savedinstancestate) { // todo auto-generated method stub super.oncreate(savedinstancestate); setcontentview(r.layout.activity_main); new getdata().execute(); } @override public boolean oncreateoptionsmenu(menu menu) { // todo auto-generated method stub homecoming super.oncreateoptionsmenu(menu); } private class getdata extends asynctask<string, void, void>{ progressdialog pdialog; jsonparser jsp=new jsonparser(); jsonobject job; arraylist<hashmap<string, string>> arraylist; customadapter adapter; @override protected void onpreexecute() { // todo auto-generated method stub super.onpreexecute(); pdialog=new progressdialog(mainactivity.this); pdialog.setindeterminate(false); pdialog.settitle("please wait"); pdialog.setmessage("loading"); pdialog.show(); } @override protected void doinbackground(string... params) { // todo auto-generated method stub list<namevaluepair> param = new arraylist<namevaluepair>(); param.add(new basicnamevaluepair("tag", "all")); job= jsp.getjsonfromurl(url, param); try{ jsonarray jarr= job.getjsonarray("names"); (int = 0; < jarr.length(); i++) { hashmap<string, string> map = new hashmap<string, string>(); job = jarr.getjsonobject(i); // retrive json objects map.put("username", job.getstring("username")); map.put("password", job.getstring("password")); log.e("jsob", job.tostring()); // set json objects array arraylist.add(map); } } catch(jsonexception e){ e.printstacktrace(); } homecoming null; } @override protected void onpostexecute(void result) { // todo auto-generated method stub super.onpostexecute(result); listview lv= (listview) findviewbyid(r.id.list); adapter = new customadapter(mainactivity.this, arraylist); lv.setadapter(adapter); pdialog.dismiss(); } } }

you not initializing arraylist.

android android-asynctask