android - RecyclerView inside Coordinate layout -

i using recyclerview inside coordinator layout.in main.xml have save button , edit text field. on click save button need pass edit text value next xml have recyclerview. run time error occurs. happening code?

mainactivity:

public class mainactivity extends appcompatactivity implements recyclerviewadapter.onitemclicklistener { edittext textin,txtheading; button buttonadd,btnsave; linearlayout container;   private recyclerview myrecyclerview; private linearlayoutmanager linearlayoutmanager; private recyclerviewadapter myrecyclerviewadapter; private recyclerview.layoutmanager recyclermanager;  @override protected void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     setcontentview(r.layout.activity_main);     myrecyclerview = (recyclerview)findviewbyid(r.id.recyclerview_builderxml);      linearlayoutmanager =             new linearlayoutmanager(this, linearlayoutmanager.vertical, false);      myrecyclerviewadapter = new recyclerviewadapter(this);     myrecyclerviewadapter.setonitemclicklistener(this);      myrecyclerview.setadapter(myrecyclerviewadapter);     myrecyclerview.setlayoutmanager(linearlayoutmanager);      txtheading = (edittext)findviewbyid(r.id.heading);      btnsave =(button) findviewbyid(r.id.btn_save);     btnsave.setonclicklistener(new view.onclicklistener() {         @override         public void onclick(view v) {             string newname = txtheading.gettext().tostring();             intent intent = new intent(getapplicationcontext(),builderpage.class);             myrecyclerviewadapter.add(0,newname);             startactivity(intent);             toast.maketext(mainactivity.this,"you added" +newname.touppercase()+ "in view",toast.length_long).show();         }     }); }  @override     public void onitemclick(recyclerviewadapter.itemholder item, int position) {     } } 

builderpage

/*  * created niroj on 8/29/16.  */   public class builderpage extends appcompatactivity {      @bindview(r.id.edittxtsurvey)     edittext edittxtsurveyname;      @bindview(r.id.toolbar_builderxml)     toolbar toolbar1;      @bindview(r.id.recyclerview_builderxml)     recyclerview recyclerview_builder;      @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.builder_layout);         butterknife.bind(this);         setsupportactionbar(toolbar1);         getsupportactionbar().setdisplayshowtitleenabled(false);          // display menu incons menu_main xml   } 

}

and builder.xml

<?xml version="1.0" encoding="utf-8"?>   <android.support.design.widget.coordinatorlayout     xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:app="http://schemas.android.com/apk/res-auto"     android:id="@+id/coordinatorlayout"     android:layout_width="match_parent"     android:layout_height="match_parent"     android:orientation="vertical">      <android.support.v7.widget.recyclerview       android:id="@+id/recyclerview_builderxml"       android:layout_width="match_parent"       android:layout_height="match_parent"       app:layout_behavior="@string/appbar_scrolling_view_behavior"/>      <android.support.design.widget.appbarlayout       android:id="@+id/appbarlayout"       android:layout_width="match_parent"       android:layout_height="wrap_content">        <android.support.v7.widget.toolbar         android:id="@+id/toolbar_builderxml"         android:layout_width="match_parent"         android:layout_height="?attr/actionbarsize"         android:background="?attr/colorprimary"         app:layout_scrollflags="scroll|enteralways">        </android.support.v7.widget.toolbar>     </android.support.design.widget.appbarlayout>   </android.support.design.widget.coordinatorlayout> 

this adapterclass recycler

public class recyclerviewadapter extends recyclerview.adapter<recyclerviewadapter.itemholder> {      private list<string> headingname;     private onitemclicklistener onitemclicklistener;     private layoutinflater layoutinflater;      public recyclerviewadapter(context context){         layoutinflater = layoutinflater.from(context);         headingname = new arraylist<string>();     }      @override     public recyclerviewadapter.itemholder oncreateviewholder(viewgroup parent, int viewtype) {         view itemview = layoutinflater.inflate(r.layout.list_item, parent, false);         return new itemholder(itemview, this);     }      @override     public void onbindviewholder(recyclerviewadapter.itemholder holder, int position) {         holder.setitemname(headingname.get(position));      }      @override     public int getitemcount() {         return headingname.size();     }      public void setonitemclicklistener(onitemclicklistener listener){         onitemclicklistener = listener;     }      public onitemclicklistener getonitemclicklistener(){         return onitemclicklistener;     }      public interface onitemclicklistener{         public void onitemclick(itemholder item, int position);     }      public void add(int location, string iname){         headingname.add(location, iname);         notifyiteminserted(location);     }       public static class itemholder extends recyclerview.viewholder implements view.onclicklistener{          private recyclerviewadapter parent;         textview textheadingname;          public itemholder(view itemview, recyclerviewadapter parent) {             super(itemview);             itemview.setonclicklistener(this);             this.parent = parent;             textheadingname = (textview) itemview.findviewbyid(r.id.title_name);         }          public void setitemname(charsequence name){             textheadingname.settext(name);         }          public charsequence getitemname(){             return textheadingname.gettext();         }          @override         public void onclick(view v) {             final onitemclicklistener listener = parent.getonitemclicklistener();             if(listener != null){                 listener.onitemclick(this, getposition());             }         }     } } 

this manifest

<?xml version="1.0" encoding="utf-8"?> 

<application     android:allowbackup="true"     android:icon="@mipmap/ic_launcher"     android:label="@string/app_name"     android:supportsrtl="true"     android:theme="@style/apptheme" >     <!--android:theme="@style/theme.appcompat.light"--> >     <activity android:name=".mainactivity">         <intent-filter>             <action android:name="android.intent.action.main"                 android:theme ="@android:style/theme.black.notitlebar.fullscreen"/>              <category android:name="android.intent.category.launcher" />         </intent-filter>     </activity> </application> 

you haven't added activity tag builder page in manifest. in manifest add activity tag builder page

<application android:allowbackup="true" android:icon="@mipmap/ic_launcher" android:label="@string/app_name" android:supportsrtl="true" android:theme="@style/apptheme" > <!--android:theme="@style/theme.appcompat.light"--> > <activity android:name=".mainactivity">     <intent-filter>         <action android:name="android.intent.action.main"             android:theme ="@android:style/theme.black.notitlebar.fullscreen"/>          <category android:name="android.intent.category.launcher" />     </intent-filter> </activity>  <!--activity tag builderpage--> <activity android:name=".builderpage">     </activity>  </application>