android - Activity doesn't show RecyclerView - Databinding -

i tried databinding recyclerview, main_activity doesn't show recyclerview content objects. dont know point of failure is. advice.

here simple code

class: user

public class user { private string name; private int age;  public user(string name, int age) {     this.name = name;     this.age = age; } public string getname() {     return name; }  public void setname(string name) {     this.name = name; }  public int getage() {     return age; }  public void setage(int age) {     this.age = age; } } 

class: useradapter

public class useradapter extends   recyclerview.adapter<recyclerview.viewholder> { private activity host; private arraylist<user> items;  public useradapter(activity activity, arraylist<user> items) {     this.host = activity;     this.items = items;     log.i("useradaptername", items.get(0).getname().tostring()); //log shows gordon  }  @override public useradapter.itemviewholder oncreateviewholder(viewgroup parent, int viewtype) {     // inflate layout , retrieve binding     listitemsbinding binding = databindingutil.inflate(host.getlayoutinflater(),             r.layout.list_items, parent, false);;      return new itemviewholder(binding); }  @override public void onbindviewholder(recyclerview.viewholder holder, int position) {     user item = items.get(position);      itemviewholder itemviewholder = (itemviewholder)holder;     itemviewholder.binditem(item); }  @override public int getitemcount() {     return items.size(); }  static class itemviewholder extends recyclerview.viewholder {     listitemsbinding binding;      itemviewholder(listitemsbinding binding) {         super(binding.getroot());         this.binding = binding;     }      void binditem(user item) {         binding.setuser(item);         binding.executependingbindings();     } } } 

class: mainactivity

public class mainactivity extends appcompatactivity { private arraylist<user> userlist = new arraylist<user>(); private activitymainbinding binding; private useradapter adapter; @override protected void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     binding = databindingutil.setcontentview(this, r.layout.activity_main);     filldata();     adapter = new useradapter(mainactivity.this,userlist);     binding.recycler.setadapter(adapter); }   private void filldata() {     userlist.add(new user("gordon", 26));     userlist.add(new user("dick", 34));     userlist.add(new user("ivan",20)); } } 

layout: activity_main

<layout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto">  <relativelayout     android:layout_width="match_parent"     android:layout_height="match_parent">     <textview         android:layout_width="match_parent"         android:layout_height="match_parent"         android:text="activity text"/>      <android.support.v7.widget.recyclerview         android:id="@+id/recycler"         android:layout_width="match_parent"         android:layout_height="wrap_content"         />  </relativelayout> 

layout: list_items

<?xml version="1.0" encoding="utf-8"?> <layout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools">  <data>      <variable         name="user"         type="de.bp2go.recgo.user" />  </data>  <linearlayout     android:layout_width="match_parent"     android:layout_height="wrap_content"     android:orientation="vertical">                <textview                 android:layout_width="wrap_content"                 android:layout_height="wrap_content"                 android:text="@{user.name}"                 android:textappearance="?android:attr/textappearancemedium"                 android:textcolor="@android:color/black"                 tools:text="name" />              <textview                 android:layout_width="wrap_content"                 android:layout_height="wrap_content"                 android:text="@{user.age}"                 android:textcolor="@android:color/black"                 tools:text="age" />          </linearlayout> </layout> 

for me looks forgot set proper layoutmanager recyclerview.

missing line vertical list:

binding.recycler.setlayoutmanager(new linearlayoutmanager(this)); 

see example: recyclerview