added adapter and holder

app/src/main/java/com/example/recyclerview/MyAdapter.java

@@ -0,0 +1,38 @@
+package com.example.recyclerview;
+
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+
+import androidx.annotation.NonNull;
+import androidx.recyclerview.widget.RecyclerView;
+
+import java.util.ArrayList;
+
+public class MyAdapter extends RecyclerView.Adapter<MyViewHolder> {
+
+    ArrayList<String> mData;
+
+    public MyAdapter(ArrayList<String> aData) {
+        mData = aData;
+    }
+
+    @NonNull
+    @Override
+    public MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
+        LayoutInflater inflater = LayoutInflater.from(parent.getContext());
+        View newView = inflater.inflate(R.layout.one_row_layout, parent, false);
+        MyViewHolder myViewHolder = new MyViewHolder(newView);
+        return myViewHolder;
+    }
+
+    @Override
+    public void onBindViewHolder(@NonNull MyViewHolder holder, int position) {
+        holder.mTextView.setText(mData.get(position));
+    }
+
+    @Override
+    public int getItemCount() {
+        return mData.size();
+    }
+}