android - please help me get sharedpreferences saved value from other class -

i saving value in sharedpreferences in 1 class , trying access class null pointer exception. value enter url web service. please me.

urlsetting.java

public class urlsetting extends activity { edittext editurl; textview savedurl; button bsaveurl, bback;  @override public void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     setcontentview(r.layout.urlsetting);      savedurl = (textview)findviewbyid(r.id.savedurl);     editurl = (edittext)findviewbyid(r.id.editurl);     bback = (button)findviewbyid(r.id.back);     bsaveurl = (button)findviewbyid(r.id.saveurl);     bsaveurl.setonclicklistener(buttonsaveurlonclicklistener);     bback.setonclicklistener(new button.onclicklistener(){          @override         public void onclick(view arg0) {             // todo auto-generated method stub             intent intent = new intent(urlsetting.this, login.class);             /*intent.setclass(urlsetting.this, login.class);*/             startactivity(intent);         }});      loadpreferences(); } button.onclicklistener buttonsaveurlonclicklistener = new button.onclicklistener(){      @override     public void onclick(view arg0) {         // todo auto-generated method stub         savepreferences("url", editurl.gettext().tostring());         loadpreferences();     }  private void savepreferences(string key, string value){     sharedpreferences sharedpreferences = getsharedpreferences("my_shared_pref", mode_private);     sharedpreferences.editor editor = sharedpreferences.edit();     editor.putstring(key, value);     editor.commit(); }  private void loadpreferences(){     sharedpreferences sharedpreferences = getsharedpreferences("my_shared_pref", mode_private);     string strsavedurl = sharedpreferences.getstring("url", "");     savedurl.settext(strsavedurl); } 

and koneksi.java

public class koneksi{  sharedpreferences sharedpreferences = getsharedpreferences("my_shared_pref", mode_private); string url = sharedpreferences.getstring("url", ""); public koneksi(string urlml){      url= url + urlml; }  public string geturl(){      return url; } 

this logcat

> 05-21 11:39:44.542: w/keycharactermap(339): no keyboard id 0 05-21 11:39:44.542: w/keycharactermap(339): using default keymap: /system/usr/keychars/qwerty.kcm.bin 05-21 11:39:51.826: d/trylogincheck(339): here 05-21 11:39:51.826: i/system.out(339): usernametes 05-21 11:39:51.831: i/system.out(339): passwordtes12345* 05-21 11:39:51.831: d/parameters(339): username=tes&password=tes12345* 05-21 11:39:51.831: d/androidruntime(339): shutting down vm 05-21 11:39:51.831: w/dalvikvm(339): threadid=1: thread exiting uncaught exception (group=0x40015560) 05-21 11:39:51.851: e/androidruntime(339): fatal exception: main 05-21 11:39:51.851: e/androidruntime(339): java.lang.nullpointerexception 05-21 11:39:51.851: e/androidruntime(339):  @ android.content.contextwrapper.getsharedpreferences(contextwrapper.java:146) 05-21 11:39:51.851: e/androidruntime(339):  @ mobile.config.koneksi.<init>(koneksi.java:13) 05-21 11:39:51.851: e/androidruntime(339):  @ com.karismaelearning.login.trylogin(login.java:131) 05-21 11:39:51.851: e/androidruntime(339):  @ com.karismaelearning.login$3.onclick(login.java:80) 05-21 11:39:51.851: e/androidruntime(339):  @ android.view.view.performclick(view.java:2485) 05-21 11:39:51.851: e/androidruntime(339):  @ android.view.view$performclick.run(view.java:9080) 05-21 11:39:51.851: e/androidruntime(339):  @ android.os.handler.handlecallback(handler.java:587) 05-21 11:39:51.851: e/androidruntime(339):  @ android.os.handler.dispatchmessage(handler.java:92) 05-21 11:39:51.851: e/androidruntime(339):  @ android.os.looper.loop(looper.java:123) 05-21 11:39:51.851: e/androidruntime(339):  @ android.app.activitythread.main(activitythread.java:3683) 05-21 11:39:51.851: e/androidruntime(339):  @ java.lang.reflect.method.invokenative(native method) 05-21 11:39:51.851: e/androidruntime(339):  @ java.lang.reflect.method.invoke(method.java:507) 05-21 11:39:51.851: e/androidruntime(339):  @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:839) 05-21 11:39:51.851: e/androidruntime(339):  @ com.android.internal.os.zygoteinit.main(zygoteinit.java:597) 05-21 11:39:51.851: e/androidruntime(339):  @ dalvik.system.nativestart.main(native method) 05-21 11:39:54.301: i/process(339): sending signal. pid: 339 sig: 9 

please me know mistake is. don't understand what's wrong. thank much

try way:

sharedpreferences sharedpreferences;  oncreate(bundle savedinstancestate){   sharedpreferences = preferencemanager.getdefaultsharedpreferences(this);   // code.. }  private void savepreferences(string key, string value){      sharedpreferences.editor editor = sharedpreferences.edit();     editor.putstring(key, value);     editor.commit(); }  private void loadpreferences(){      string strsavedurl = sharedpreferences.getstring("url", "");     savedurl.settext(strsavedurl); } 

---

edited:

    public class koneksi{      sharedpreferences sharedpreferences;     context myc;     string url = "";      public koneksi(context con){        myc = con;        sharedpreferences = preferencemanager.getdefaultsharedpreferences(con);     }       public koneksi(string urlml){          url= url + urlml;     }       public string geturl(){         string url = sharedpreferences.getstring("url", "");         return url;     } } 

for call above class activity:

koneksi ob = new koneksi(this); string url = ob.geturl();