php - E/AndroidRuntime(1163): FATAL EXCEPTION: main -

this code,

i want execute menurestaurant.php in server(apache tomcat) connect database, think problem in server address

public class menu2 extends listactivity {      @override     protected void oncreate(bundle savedinstancestate) {         log.i("","avantoncreatemenu2");         super.oncreate(savedinstancestate);         log.i("","oncreatemenu2");         //setcontentview(r.layout.activity_menu2);         string result = null;          inputstream = null;          jsonobject json_data=null;          arraylist<namevaluepair> namevaluepairs = new arraylist<namevaluepair>();          arraylist<string> donnees = new arraylist<string>();          try{               log.i("","avantappelphp");              //commandes httpclient                 httpclient httpclient = new defaulthttpclient();                httppost httppost = new httppost("http://10.0.2.2:8080/menurestaurant.php");                 log.i("","apresappelphp");                httppost.setentity(new urlencodedformentity(namevaluepairs));               httpresponse response = httpclient.execute(httppost);                    httpentity entity = response.getentity();                 = entity.getcontent();              }              catch(exception e){               log.i("taghttppost",""+e.tostring());                     toast.maketext(getbasecontext(),e.tostring() ,toast.length_long).show();                }                //conversion de la réponse en chaine de caractère                 try                 {                  bufferedreader reader = new bufferedreader(new inputstreamreader(is,"utf-8"));                   stringbuilder sb  = new stringbuilder();                   string line = null;                   while ((line = reader.readline()) != null)                  {                  sb.append(line + "\n");                  }                   is.close();                   result = sb.tostring();                 }                 catch(exception e)                 {                  log.i("tagconvertstr",""+e.tostring());                 }                 //recuperation des donnees json                 try{                   jsonarray jarray = new jsonarray(result);                       for(int i=0;i<jarray.length();i++)                      {                             json_data = jarray.getjsonobject(i);                            donnees.add(json_data.getstring("nom"));                            //r.add(json_data.getstring("categorie"));                         }                         setlistadapter(new arrayadapter<string>(this, android.r.layout.simple_expandable_list_item_1, donnees));                     }                     catch(jsonexception e){                      log.i("tagjsonexp",""+e.tostring());                     } catch (parseexception e) {                      log.i("tagjsonpars",""+e.tostring());                }              }         } 

and log:

07-18 12:10:04.997: d/dalvikvm(1163): gc_for_alloc freed 47k, 7% free 2614k/2792k, paused 54ms, total 58ms 07-18 12:10:05.027: i/dalvikvm-heap(1163): grow heap (frag case) 3.283mb 635812-byte allocation 07-18 12:10:05.117: d/dalvikvm(1163): gc_for_alloc freed 2k, 6% free 3233k/3416k, paused 86ms, total 86ms 07-18 12:10:05.207: d/dalvikvm(1163): gc_concurrent freed <1k, 5% free 3248k/3416k, paused 10ms+5ms, total 93ms 07-18 12:10:05.547: i/choreographer(1163): skipped 62 frames!  application may doing work on main thread. 07-18 12:10:05.607: d/gralloc_goldfish(1163): emulator without gpu emulation detected. 07-18 12:10:21.777: i/(1163): avantswitch 07-18 12:10:21.848: i/(1163): apresswitch 07-18 12:10:21.848: i/choreographer(1163): skipped 38 frames!  application may doing work on main thread. 07-18 12:10:22.007: i/(1163): avantoncreatemenu2 07-18 12:10:22.007: i/(1163): oncreatemenu2 07-18 12:10:22.017: i/(1163): avantappelphp 07-18 12:10:22.107: i/(1163): apresappelphp 07-18 12:10:22.668: i/taghttppost(1163): android.os.networkonmainthreadexception 07-18 12:10:22.877: d/dalvikvm(1163): gc_concurrent freed 141k, 8% free 3543k/3816k, paused 71ms+117ms, total 413ms 07-18 12:10:22.947: i/tagconvertstr(1163): java.lang.nullpointerexception: lock == null 07-18 12:10:22.988: d/androidruntime(1163): shutting down vm 07-18 12:10:22.997: w/dalvikvm(1163): threadid=1: thread exiting uncaught exception (group=0x40a71930) 07-18 12:10:23.147: e/androidruntime(1163): fatal exception: main 07-18 12:10:23.147: e/androidruntime(1163): java.lang.runtimeexception: unable start activity componentinfo{com.example.catalogue/com.example.catalogue.menu2}: java.lang.nullpointerexception 07-18 12:10:23.147: e/androidruntime(1163):     @ android.app.activitythread.performlaunchactivity(activitythread.java:2180) 07-18 12:10:23.147: e/androidruntime(1163):     @ android.app.activitythread.handlelaunchactivity(activitythread.java:2230) 07-18 12:10:23.147: e/androidruntime(1163):     @ android.app.activitythread.access$600(activitythread.java:141) 07-18 12:10:23.147: e/androidruntime(1163):     @ android.app.activitythread$h.handlemessage(activitythread.java:1234) 07-18 12:10:23.147: e/androidruntime(1163):     @ android.os.handler.dispatchmessage(handler.java:99) 

i used @ip doesn't change me please