Android RecyclerView.Adapter basic use

MainActivity.java

public class MainActivity extends AppCompatActivity {

    private RecyclerView mRecyclerView;
    private MyAdapter mMyAdapter;
    private LinearLayoutManager mLayoutManager;
    private List<String> list;

    @Override
    protected void onCreate(final Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initData();

        mRecyclerView = findViewById(R.id.recycler_view);
        mMyAdapter = new MyAdapter(list);
        mLayoutManager = new LinearLayoutManager(this);
        mRecyclerView.setLayoutManager(mLayoutManager);
        mRecyclerView.setAdapter(mMyAdapter);
    }

    private void initData() {
        list = new ArrayList<>();
        for (int i = 0; i <= 20; i++) {
            list.add("Item " + i);
        }
    }
}

Adapter.java

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {

    //数据源
    private List<String> mList;

    public MyAdapter(List<String> list) {
        mList = list;
    }

    //返回item个数
    @Override
    public int getItemCount() {
        return mList.size() ;
    }

    //创建ViewHolder
    @NonNull
    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    return new NormalHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.item, parent, false));
    }

    //填充视图
    @Override
    public void onBindViewHolder(@NonNull final MyAdapter.ViewHolder holder, final int position) {
        holder.mView.setText(mList.get(position));
    }

    public class ViewHolder extends RecyclerView.ViewHolder {
        public TextView mView;

        public ViewHolder(View itemView) {
            super(itemView);
            mView = itemView.findViewById(R.id.text_view);
        }
    }
}