According to this question this is the best way to implement clicking on the item of RecyclerView
Firstly create a file values/ids.xml and put this in it:
<?xml version="1.0" encoding="utf-8"?>
<resources>
    <item name="item_click_support" type="id" />
</resources>
then add the code below to your source
for Java
Copy the following helper class to your project
public class ItemClickSupport {
    private final RecyclerView mRecyclerView;
    private OnItemClickListener mOnItemClickListener;
    private OnItemLongClickListener mOnItemLongClickListener;
    private View.OnClickListener mOnClickListener = new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if (mOnItemClickListener != null) {
                // ask the RecyclerView for the viewHolder of this view.
                // then use it to get the position for the adapter
                RecyclerView.ViewHolder holder = mRecyclerView.getChildViewHolder(v);
                mOnItemClickListener.onItemClicked(mRecyclerView, holder.getAdapterPosition(), v);
            }
        }
    };
    private View.OnLongClickListener mOnLongClickListener = new View.OnLongClickListener() {
        @Override
        public boolean onLongClick(View v) {
            if (mOnItemLongClickListener != null) {
                RecyclerView.ViewHolder holder = mRecyclerView.getChildViewHolder(v);
                return mOnItemLongClickListener.onItemLongClicked(mRecyclerView, holder.getAdapterPosition(), v);
            }
            return false;
        }
    };
    private RecyclerView.OnChildAttachStateChangeListener mAttachListener
            = new RecyclerView.OnChildAttachStateChangeListener() {
        @Override
        public void onChildViewAttachedToWindow(View view) {
            // every time a new child view is attached add click listeners to it
            if (mOnItemClickListener != null) {
                view.setOnClickListener(mOnClickListener);
            }
            if (mOnItemLongClickListener != null) {
                view.setOnLongClickListener(mOnLongClickListener);
            }
        }
        @Override
        public void onChildViewDetachedFromWindow(View view) {
        }
    };
    private ItemClickSupport(RecyclerView recyclerView) {
        mRecyclerView = recyclerView;
        // the ID must be declared in XML, used to avoid
        // replacing the ItemClickSupport without removing
        // the old one from the RecyclerView
        mRecyclerView.setTag(R.id.item_click_support, this);
        mRecyclerView.addOnChildAttachStateChangeListener(mAttachListener);
    }
    public static ItemClickSupport addTo(RecyclerView view) {
        // if there's already an ItemClickSupport attached
        // to this RecyclerView do not replace it, use it
        ItemClickSupport support = (ItemClickSupport) view.getTag(R.id.item_click_support);
        if (support == null) {
            support = new ItemClickSupport(view);
        }
        return support;
    }
    public static ItemClickSupport removeFrom(RecyclerView view) {
        ItemClickSupport support = (ItemClickSupport) view.getTag(R.id.item_click_support);
        if (support != null) {
            support.detach(view);
        }
        return support;
    }
    public ItemClickSupport setOnItemClickListener(OnItemClickListener listener) {
        mOnItemClickListener = listener;
        return this;
    }
    public ItemClickSupport setOnItemLongClickListener(OnItemLongClickListener listener) {
        mOnItemLongClickListener = listener;
        return this;
    }
    private void detach(RecyclerView view) {
        view.removeOnChildAttachStateChangeListener(mAttachListener);
        view.setTag(R.id.item_click_support, null);
    }
    public interface OnItemClickListener {
        void onItemClicked(RecyclerView recyclerView, int position, View v);
    }
    public interface OnItemLongClickListener {
        boolean onItemLongClicked(RecyclerView recyclerView, int position, View v);
    }
}
Usage:
just call it from activity / fragment like the following
ItemClickSupport.addTo(mRecyclerView)
        .setOnItemClickListener(new ItemClickSupport.OnItemClickListener() {
    @Override
    public void onItemClicked(RecyclerView recyclerView, int position, View v) {
        // do it
   Toast.makeText(v.getContext(), "Item is clicked", Toast.LENGTH_SHORT).show();
    }
});
(it also supports long item click)
Source
2
solved Display a toast after clicking an item in a RecyclerView