I'm try to do implement searchview in recycleview.....but its not working

Question

I am trying to implement searchview in recycleview but that is not working.
No type of error shows, I can't figure out where my mistake is.

This is the search activity which contain recycleview and adapter class. I just create demo to search item in recycleview:

SearchActivity.java

public class New_Search extends AppCompatActivity
{
    private RecyclerView recyclerView;
    DummyAdapter mAdapter;
    List<Lead_Contacts> movieList;
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.dummysearch);
        movieList=new ArrayList<>();
        Lead_Contacts contacts = new Lead_Contacts("Mad Max: Fury Road", "Action & Adventure", "29/04/2016");
        movieList.add(contacts);
        contacts= new Lead_Contacts("Inside Out", "Animation, Kids & Family", "29/04/2016");
        movieList.add(contacts);
        contacts = new Lead_Contacts("Star Wars: Episode VII - The Force Awakens", "Action", "29/04/2016");
        movieList.add(contacts);
        contacts= new Lead_Contacts("Shaun the Sheep", "Animation", "29/04/2016");
        movieList.add(contacts);
        contacts= new Lead_Contacts("Shaun the Sheep", "Animation", "29/04/2016");
        movieList.add(contacts);
        contacts= new Lead_Contacts("Shaun the Sheep", "Animation", "29/04/2016");
        movieList.add(contacts);
        contacts= new Lead_Contacts("Shaun the Sheep", "Animation", "29/04/2016");
        movieList.add(contacts);
        movieList.add(contacts);
        recyclerView = (RecyclerView)findViewById(R.id.recycler_view1);
        RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(this);
        recyclerView.setLayoutManager(mLayoutManager);
        recyclerView.setItemAnimator(new DefaultItemAnimator());
        mAdapter=new DummyAdapter(getApplicationContext(),movieList);
        recyclerView.setAdapter(mAdapter);
        mAdapter.notifyDataSetChanged();

    }
    public class DummyAdapter  extends RecyclerView.Adapter<DummyAdapter.Customview_holder>
    {
        private Context context;
        private List<Lead_Contacts> listcontacts;
        Lead_Contacts leadcontacts;
        List<Lead_Contacts> leadlist;
        // ClickListener listener;
        public CardView mCardView;
        public DummyAdapter(Context context, List<Lead_Contacts> listcontacts)
        {

            this.context=context;
            this.listcontacts=listcontacts;
        }

        @Override
        public Customview_holder onCreateViewHolder(ViewGroup parent, int viewType)
        {
            View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.seachrecyclelis, parent, false);
            //Customview_holder viewHolder = new Customview_holder(view);
            return new Customview_holder(view);
        }

        @Override
        public void onBindViewHolder(Customview_holder customViewHolder, int position)
        {
            //customViewHolder.mCardView.setTag(position);
            // System.out.println("call binder method");
            Lead_Contacts leadcontacts = listcontacts.get(position);
            customViewHolder.cust_name_textView.setText(leadcontacts.getCustomer_name());
            customViewHolder.eventname_textView.setText(leadcontacts.getEvent_name());
            customViewHolder.date_textView.setText(leadcontacts.getDatetime());

        }


        public int getItemCount()
        {
            return listcontacts.size();
        }

        public void filter(String trim) {
        }


        public class Customview_holder extends RecyclerView.ViewHolder {
            //public View mCardView;
            protected TextView cust_name_textView;
            protected TextView eventname_textView;
            protected TextView date_textView;
            public Customview_holder(View itemView)
            {

                super(itemView);
                // mCardView = (CardView) itemView.findViewById(R.id.cardview);
                // mCardView.setOnClickListener(this);
                System.out.println("call binder method");
                this.cust_name_textView = (TextView)itemView.findViewById(R.id.lead_cust_name);
                this.eventname_textView = (TextView)itemView.findViewById(R.id.lead_eventname);
                this.date_textView = (TextView)itemView.findViewById(R.id.leaddate);
            }

//        public void onClick(View v)
//        {
//            int position = (int) v.getTag();
//            Toast.makeText(v.getContext(),Integer.toString(position), Toast.LENGTH_SHORT).show();
//
//        }
        }
    }
    public boolean onCreateOptionsMenu(Menu menu)
    {
        getMenuInflater().inflate(R.menu.lead_search, menu);
        super.onCreateOptionsMenu(menu);
        MenuItem searchItem = menu.findItem(R.id.action_search);
        SearchView searchView = (SearchView) MenuItemCompat.getActionView(searchItem);
        //*** setOnQueryTextFocusChangeListener ***
        searchView.setOnQueryTextFocusChangeListener(new View.OnFocusChangeListener() {


            public void onFocusChange(View v, boolean hasFocus)
            {

            }
        });

        searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {

            @Override
            public boolean onQueryTextSubmit(String query)
            {
                return false;
            }

            @Override
            public boolean onQueryTextChange(String searchQuery) {
                mAdapter.filter(searchQuery.toString().trim());
                recyclerView.invalidate();
                return true;
            }
        });

        MenuItemCompat.setOnActionExpandListener(searchItem, new MenuItemCompat.OnActionExpandListener() {
            @Override
            public boolean onMenuItemActionCollapse(MenuItem item) {
                // Do something when collapsed
                return true;  // Return true to collapse action view
            }

            @Override
            public boolean onMenuItemActionExpand(MenuItem item) {
                // Do something when expanded
                return true;  // Return true to expand action view
            }
        });
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item)
    {
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_search)
    {

    return true;
}
    return super.onOptionsItemSelected(item);
}

}

This is the menu.xml file which puts the searchview on actionbar:

<menu 
     xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
>

    <item 
          android:id="@+id/action_search"
          android:icon="@drawable/search"
          android:title="@string/action_search"
          app:actionViewClass="android.support.v7.widget.SearchView"
          app:showAsAction="ifRoom|collapseActionView"
    />

</menu>

Answer 1

You forgot to implement your filter method:

    public void filter(String trim) {
    }

First declare a filtered list in your DummyAdapter:

private List<Lead_Contacts> filteredContactList;

Then change the constructor to get a copy of the list:

    public DummyAdapter(Context context, List<Lead_Contacts> listcontacts)
    {

        this.context=context;
        this.listcontacts=listcontacts;
        this.filteredContactList = new ArrayList<>(listcontacts);
    }

Change your getItemCount to return the size of the filtered list:

    public int getItemCount()
    {
        return filteredContactList.size();
    }

Then implement your filter method:

    public void filter(String trim) {
            filteredContactList.clear();
            for (Lead_Contacts contact : listcontacts) {
                if (contact. getCustomer_name().toLowerCase().contains(trim.toLowerCase())) {
                    filteredContactList.add(contact);
                }
            }
    }