How to add Onclick listener to recycler view

You can handle this using two ways

1). Gesture touch https://www.google.co.in/amp/sapandiwakar.in/recycler-view-item-click-handler/amp/

2).Using interface in adapter https://antonioleiva.com/recyclerview-listener/

I suggest second way using interface

How to use interface for recycleritemclick

public class RecycleViewAdapter extends 
  RecyclerView.Adapter<RecycleViewHolder> {// Recyclerview will extend to
  private List<FileName> fileNames;
  private Context context;

//declare interface 
  private OnItemClicked onClick;

//make interface like this
  public interface OnItemClicked {
        void onItemClick(int position);
  }

  public RecycleViewAdapter(Context context,List<FileName> fileNames) {
    this.context = context;
    this.fileNames = fileNames;
  }

Now assign click to interface

@Override
public void onBindViewHolder(RecycleViewHolder holder, final int position) {
  //............//
  holder.title.setOnClickListener(new View.OnClickListener() {
     @Override
     public void onClick(View v) {
        onClick.onItemClick(position);
     }
  });
}

At the end of the adapter class up from finishing bracket make one method to assign itemclick to interface

public void setOnClick(OnItemClicked onClick){
    this.onClick=onClick;
}

In MainActivity.java Bind the item click with adapter

public class MainActivity extends Activity implements OnItemClicked {
 
    private RecyclerView mRecyclerView;
    private CityAdapter mAdapter;
    private List<City> cities;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_city);

        mRecyclerView = (RecyclerView)findViewById(R.id.list);
        mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
        
        mAdapter = new CityAdapter(cities, R.layout.row_city, this);
        mRecyclerView.setAdapter(mAdapter);
 
        mAdapter.setOnClick(MainActivity.this); // Bind the listener
    }
 
    @Override
    public void onItemClick(int position) {
    // The onClick implementation of the RecyclerView item click
    //ur intent code here
    }
}

For Kotlin code please refer How to handle recyclerview item click in kotlin?

More queries? comment.

First add this class to your package

public class MyTouchListener implements RecyclerView.OnItemTouchListener {


/*Change these as per your need*/
private static final int SWIPE_MIN_DISTANCE = 120;
private static final int SWIPE_THRESHOLD_VELOCITY = 200;
private static final int SWIPE_MAX_OFF_PATH = 250;

private OnTouchActionListener mOnTouchActionListener;
private GestureDetectorCompat mGestureDetector;

public static interface OnTouchActionListener {
    public void onLeftSwipe(View view, int position);
    public void onRightSwipe(View view, int position);
    public void onClick(View view, int position);
}

public MyTouchListener(Context context, final RecyclerView recyclerView,
                             OnTouchActionListener onTouchActionListener){

    mOnTouchActionListener = onTouchActionListener;
    mGestureDetector = new GestureDetectorCompat(context,new GestureDetector.SimpleOnGestureListener(){

        @Override
        public boolean onSingleTapConfirmed(MotionEvent e) {
            // Find the item view that was swiped based on the coordinates
            View child = recyclerView.findChildViewUnder(e.getX(), e.getY());
            int childPosition = recyclerView.getChildPosition(child);
            mOnTouchActionListener.onClick(child, childPosition);
            return false;
        }

        @Override
        public boolean onFling(MotionEvent e1, MotionEvent e2,
                               float velocityX, float velocityY) {

            try {
                if (Math.abs(e1.getY() - e2.getY()) > SWIPE_MAX_OFF_PATH) {
                    return false;
                }

                // Find the item view that was swiped based on the coordinates
                View child = recyclerView.findChildViewUnder(e1.getX(), e1.getY());
                int childPosition = recyclerView.getChildPosition(child);

                // right to left swipe
                if (e1.getX() - e2.getX() > SWIPE_MIN_DISTANCE && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {

                    if (mOnTouchActionListener != null && child != null) {
                        mOnTouchActionListener.onLeftSwipe(child, childPosition);
                    }

                } else if (e2.getX() - e1.getX() > SWIPE_MIN_DISTANCE && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
                    if (mOnTouchActionListener != null && child != null) {
                        mOnTouchActionListener.onRightSwipe(child, childPosition);
                    }
                }
            } catch (Exception e) {
                // nothing
            }

            return false;
        }
    });
}

@Override
public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e) {
    mGestureDetector.onTouchEvent(e);
    return false;
}

@Override
public void onTouchEvent(RecyclerView rv, MotionEvent e) {
}

@Override
public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {
    // do nothing
}}

Then addOnItemTouchListener like this:

myRecyclerView.addOnItemTouchListener(new MyTouchListener(mContext,
            myRecyclerView,
            new MyTouchListener.OnTouchActionListener() {
                @Override
                public void onLeftSwipe(View view, int position) {//code as per your need
                }

                @Override
                public void onRightSwipe(View view, int position) {//code as per your need
                }

                @Override
                public void onClick(View view, int position) {//code as per your need
                }
            }));

Change your adapter to this

    public class RecycleViewAdapter extends
        RecyclerView.Adapter<RecycleViewHolder> {// Recyclerview will extend to
    private List<FileName> fileNames;
    private Context context;
    private OnItemClicked listener;

    public RecycleViewAdapter(Context context, List<FileName> fileNames, OnItemClicked  listener) {
        this.context = context;
        this.fileNames = fileNames;
        this.listener = listener;
    }

    public BookingHistoryFragment() {
        // Required empty public constructor
    }

    @Override
    public RecycleViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        LayoutInflater mInflater = LayoutInflater.from(parent.getContext());

        ViewGroup mainGroup = (ViewGroup) mInflater.inflate(
                R.layout.grid_item, parent, false);
        RecycleViewHolder listHolder = new RecycleViewHolder(mainGroup);

        return listHolder;

    }

    @Override
    public void onBindViewHolder(RecycleViewHolder holder, final int position) {
        final FileName model = fileNames.get(position);
        RecycleViewHolder mainHolder = (RecycleViewHolder) holder;// holder
        mainHolder.title.setText(model.getName());
        mainHolder.note.setText(model.getShorttext());

        // Add click listener for root view
        view.getRootView().setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            listener.onItemClick(view, position)
        }
        });
    }

    @Override
    public int getItemCount() {
        return (null != fileNames ? fileNames.size() : 0);
    }

    public interface OnItemClicked {
        void onItemClick(View view, int position);
    }
}

Now pass ItemClickInterface to the adapter constructor while initializing from activity or fragment. Instead of:

RecycleViewAdapter adapter = new RecycleViewAdapter(this, filenames);

Use this:

RecycleViewAdapter adapter = new RecycleViewAdapter(this, filenames, new RecycleViewAdapter.OnItemClicked () {
@Override
      public void onItemClick(View view, Position position) {

      }
});

Simplest solution would be to access the "itemView" public variable of holder class and set onClickListener on this.

@Override
public void onBindViewHolder(ViewHolder holder, final int position) {
        holder.itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(context, NewActivity.class);
                intent.putExtra("FileName", list.get(position));
                context.startActivity(intent);
            }
        });        
}