arraylist - Why my hashmap is null Android? -

i trying value hashmap (from listviewrestaurants) can pass latitude , longitude mapsactivity reason hashmap return null ... can me.

public class listviewrestaurants extends activity {      static listview listview;     static arraylist<hashmap<string, string>> arrlist;      @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.activity_list);          listview = (listview) findviewbyid(r.id.listiew);         arrlist = new arraylist<hashmap<string, string>>();          string json_str = getjsondata();          try {             jsonarray jarray = new jsonarray(json_str);              (int = 0; < jarray.length(); i++) {                 jsonobject json = null;                 json = jarray.getjsonobject(i);                  hashmap<string, string> map1 = new hashmap<string, string>();                  // adding each child node hashmap key => value                 map1.put("id", json.getstring("id"));                 map1.put("businessname", json.getstring("businessname"));                 map1.put("addressline1", json.getstring("addressline1"));                 map1.put("addressline2", json.getstring("addressline2"));                 map1.put("addressline3", json.getstring("addressline3"));                 map1.put("postcode", json.getstring("postcode"));                 map1.put("ratingvalue", json.getstring("ratingvalue"));                 map1.put("ratingdate", json.getstring("ratingdate"));                 map1.put("distancekm", json.getstring("distancekm"));                 map1.put("latitude", json.getstring("latitude"));                 map1.put("longitude", json.getstring("longitude"));                  int name = json.getint("ratingvalue");                 if(name == 5){                     map1.put("image", string.valueof(r.drawable.ic_launcher_web));                 }                 else if(name==4){                     //map1.put("image", string.valueof(r.drawable.ic_launcher_web));                 }                 else if(name==3){                     // map1.put("image", string.valueof(r.drawable.ic_launcher_web));                 }                 else if(name==2){                     // map1.put("image", string.valueof(r.drawable.ic_launcher_web));                 }                 else if(name==1){                     // map1.put("image", string.valueof(r.drawable.ic_launcher_web));                 }                 else if(name==0){                     // map1.put("image", string.valueof(r.drawable.ic_launcher_web));                 }                 else if(name==-1){                     map1.put("ratingvalue", "exempt");                 }                 // adding hashlist arraylist                 arrlist.add(map1); //                intent intent = new intent(this,mapsactivity.class); //                intent.putextra("map", map1);             }           } catch (jsonexception e) {             e.printstacktrace();         }          if (!arrlist.isempty()) {             listadapter adapter = new simpleadapter(this, arrlist,                     r.layout.list_item, new string[]{"id", "businessname",                     "addressline1", "addressline2", "addressline3", "postcode",                     "ratingvalue", "ratingdate", "distancekm", "image"},                     new int[]{r.id.restaurantid, r.id.businessname,                             r.id.adr1, r.id.adr2, r.id.adr3, r.id.postcode,                             r.id.rating, r.id.ratingdate, r.id.distance, r.id.image});               listview.setadapter(adapter);         }     }      private string getjsondata() {         strictmode.setthreadpolicy(new strictmode.threadpolicy.builder()                 .detectdiskreads()                 .detectdiskwrites()                 .detectnetwork()   // or .detectall() detectable problems                 .penaltylog()                 .build());          string str = "";         intent intent  = getintent();         string latitude = intent.getstringextra("lat");         string longtitude = intent.getstringextra("lon");         httpresponse response;         httpclient myclient = new defaulthttpclient();         httppost myconnection = new httppost("http://sandbox.kriswelsh.com/hygieneapi/hygiene.php?op=s_loc&lat="+latitude+"&long="+longtitude);          try {             response = myclient.execute(myconnection);             str = entityutils.tostring(response.getentity(), "utf-8");          } catch (clientprotocolexception e) {             e.printstacktrace();         } catch (ioexception e) {             e.printstacktrace();         }          return str;     }  }  

here trying retrieve details hashamp (latitude , longitude) listviewrestuarants null values.

import android.content.intent; import android.support.v4.app.fragmentactivity; import android.os.bundle; import android.util.log;  import com.google.android.gms.maps.cameraupdatefactory; 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.latlng; import com.google.android.gms.maps.model.markeroptions;  import java.util.hashmap;  public class mapsactivity extends fragmentactivity implements onmapreadycallback {      private googlemap mmap;     static string x;     @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);         //get value array class         intent intent = getintent();         hashmap<string, string> hashmap = (hashmap<string, string>)intent.getserializableextra("map"); system.out.println(hashmap)          // log.v("hashmaptest", hashmap.get("longtitude"));     }      /**      * 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;          // add marker in sydney , move camera         latlng sydney = new latlng(-34, 151);         mmap.addmarker(new markeroptions().position(sydney).title(x));         mmap.movecamera(cameraupdatefactory.newlatlng(sydney));     } }  

this main class display tab view (for more information)

import android.app.tabactivity; import android.content.intent; import android.os.bundle; import android.widget.tabhost;  public class mainactivity extends tabactivity {      @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.activity_main);          // create tabhost contain tabs         tabhost tabhost = (tabhost)findviewbyid(android.r.id.tabhost);          tabhost.tabspec tab1 = tabhost.newtabspec("first tab");         tabhost.tabspec tab2 = tabhost.newtabspec("second tab");          // set tab name , activity         // opened when particular tab selected         tab1.setindicator("restaurant");         tab1.setcontent(new intent(this, listviewrestaurants.class));          tab2.setindicator("map");         tab2.setcontent(new intent(this, restaurantmap.class));          /** add tabs  tabhost display. */         tabhost.addtab(tab1);         tabhost.addtab(tab2);     } } 

the issue setting different key in map trying fetch value corresponding different key -

map1.put("longitude", json.getstring("longitude")); //setting "longitude"  log.v("hashmaptest", hashmap.get("longtitude")); //getting "longtitude" 

apparently, there no key "longtitude" in map.

best practice have constants keys , use insertion , retrieval , avoid such issues , not waste time debugging in also.