@Override
    public void onBindViewHolder(final AdapterViewHolder holder, final int position) {


        holder.imagem.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Toast.makeText(context, "posicao "+position,Toast.LENGTH_SHORT).show();
                Toast.makeText(context, "posicao "+holder.getAdapterPosition(),Toast.LENGTH_SHORT).show();
            }
        });


    }

public static class MyViewHolder extends RecyclerView.ViewHolder
                                 implements View.OnClickListener{

    private final ImageView imageView;

    public MyViewHolder(View v) {
        super(v);

        v.setOnClickListener(this);
        imageView = (ImageView) v.findViewById(R.id.imageView);
    }

    //Implementa View.OnClickListener
    @Override
    public void onClick(View v) {
        Log.d(TAG, "Elemento " + getAdapterPosition() + " clicado.");
    }
}

@Override
public ViewHolder onCreateViewHolder(ViewGroup viewGroup, int viewType) {

    View v = LayoutInflater.from(viewGroup.getContext())
            .inflate(R.layout.row_item, viewGroup, false);

    return new MyViewHolder(v);
}

public interface ItemClickListener {

    void onItemClick(int position);
}

private static ItemClickListener itemClickListener;

public void setOnItemClickListener(ItemClickListener itemClickListener){
    this.itemClickListener = itemClickListener;
}

public class MyViewHolder extends RecyclerView.ViewHolder
                                 implements View.OnClickListener{

    private final ImageView imageView;

    public MyViewHolder(View v) {
        super(v);

        v.setOnClickListener(this);
        imageView = (ImageView) v.findViewById(R.id.imageView);
    }

    //Implementa View.OnClickListener
    @Override
    public void onClick(View v) {

        if(itemClickListener != null) {
            itemClickListener.onItemClick(getAdapterPosition());
        }
    }
}

adapter.setOnItemClickListener(new ItemClickListener() {
    @Override
    public void onItemClick(int position) {
        Log.d(TAG, "Elemento " + position + " clicado.");
    }
});

@Override
    public void onBindViewHolder(final AdapterViewHolder holder, final int position) {

        holder.imagem.setTag(position);
        holder.imagem.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                int clickPosition = (int) view.getTag();

                Toast.makeText(context, "posicao "+clickPosition,Toast.LENGTH_SHORT).show();

            }
        });


    }