android - How do I save and display String using SharedPreference? -

i have following code application force closes before opening. have edittext, button , textview. clicking button should save string edittext sharedpreference , sharedpreference string should displayed in textview. doing wrong here.

package com.jainchiranjeev.arduinoremote.newcomponents;  import android.content.sharedpreferences; import android.support.v7.app.actionbaractivity; import android.os.bundle; import android.support.v7.app.appcompatactivity; import android.view.menu; import android.view.menuitem; import android.view.view; import android.widget.button; import android.widget.edittext; import android.widget.textview;   public class mainactivity extends appcompatactivity {      edittext edittext;     button confirm;     textview text;      public static final string name = "myprefs";     sharedpreferences.editor editor = getsharedpreferences(name, mode_world_writeable).edit();      @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.activity_main);          confirm.setonclicklistener(new view.onclicklistener() {             @override             public void onclick(view v) {                 editor.putstring("name", string.valueof(edittext.gettext()));                 editor.commit();             }         });          sharedpreferences prefs = getsharedpreferences(name, mode_world_readable);         string restoredtext = prefs.getstring("name","your name appears here");         text.settext(restoredtext);     }      @override     public boolean oncreateoptionsmenu(menu menu) {         // inflate menu; adds items action bar if present.         getmenuinflater().inflate(r.menu.menu_main, menu);         return true;     }      @override     public boolean onoptionsitemselected(menuitem item) {         // handle action bar item clicks here. action bar         // automatically handle clicks on home/up button, long         // specify parent activity in androidmanifest.xml.         int id = item.getitemid();          //noinspection simplifiableifstatement         if (id == r.id.action_settings) {             return true;         }          return super.onoptionsitemselected(item);     } } 

get shared preferences in oncreatemethod , dont initialize editor field of class.

sharedpreferences.editor editor = context.getsharedpreferences(             preferences_name, context.mode_multi_process | context.mode_private).edit();     editor.putstring(setting, value);     editor.apply(); 

also take trainning http://developer.android.com/training/basics/data-storage/shared-preferences.html