@Override
public View getView(final int position, View convertView, ViewGroup parent) {
    Holder holder = new Holder();
    View rowView = inflater.inflate(R.layout.item_list, null);
    holder.tv = (TextView) rowView.findViewById(R.id.text);
    holder.tv.setText(result[position]);
    return rowView;
}

@Override
public View getView(final int position, View convertView, ViewGroup parent) {
    if (convertView == null) {
        rootView = inflater.inflate(R.layout.item_list, null);
        Holder holder = new Holder(); // ViewHolder을 생성
        holder.tv = (TextView) rowView.findViewById(R.id.text);
        rootView.setTag(viewHolder); // setTag
    } else {
        rootView = convertView;
        holder = (Holder) rootView.getTag(); // rootView에서 holder을 꺼내온다
    }

    holder.tv.setText(result[position]);
    return rootView;
}

// use a linear layout manager
mLayoutManager = new LinearLayoutManager(this);
mRecyclerView.setLayoutManager(mLayoutManager);

// use a staggered grid layout manager
mGridLayoutManager = new new GridLayoutManager(this, 3);
mRecyclerView.setLayoutManager(mGridLayoutManager);

// use a staggered grid layout manager
mStgaggeredGridLayoutManager = new StaggeredGridLayoutManager(2, StaggeredGridLayoutManager.VERTICAL);
mRecyclerView.setLayoutManager(mStgaggeredGridLayoutManager);

// Provide a reference to the views for each data item
// Complex data items may need more than one view per item, and
// you provide access to all the views for a data item in a view holder
public class ViewHolder extends RecyclerView.ViewHolder {
    // each data item is just a string in this case
    public TextView mTextView;
    public ViewHolder(TextView v) {
        super(v);
        mTextView = v;
    }
}

public class ViewHolder extends RecyclerView.ViewHolder {

  private TextView textView;

  public ViewHolder(Context context, ViewGroup parent) {
      super(LayoutInflater.from(context).inflate(R.layout.item_large_view, parent, false));

      textView = (TextView) itemView.findViewById(R.id.tv_message);
  }
}

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

    // 아이템 리스트
    private String[] mDataset;

    // Provide a suitable constructor (depends on the kind of dataset)
    public MyAdapter(String[] myDataset) {
        mDataset = myDataset;
    }

    // Create new views (invoked by the layout manager)
    @Override
    public MyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,
                                                   int viewType) {
        // create a new view
        View v = LayoutInflater.from(parent.getContext())
                               .inflate(R.layout.my_text_view, parent, false);
        // set the view's size, margins, paddings and layout parameters
        ...
        ViewHolder vh = new ViewHolder(v);
        return vh;
    }

    // Replace the contents of a view (invoked by the layout manager)
    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        // - get element from your dataset at this position
        // - replace the contents of the view with that element
        holder.mTextView.setText(mDataset[position]);
    }

    // Return the size of your dataset (invoked by the layout manager)
    @Override
    public int getItemCount() {
        return mDataset.length;
    }
}

// 아이템 리스트
private String[] mDataset;

// Return the size of your dataset (invoked by the layout manager)
@Override
public int getItemCount() {
    return mDataset.length;
}

// Create new views (invoked by the layout manager)
@Override
public MyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,
                                               int viewType) {
    // create a new view
    View v = LayoutInflater.from(parent.getContext())
                           .inflate(R.layout.my_text_view, parent, false);
    // set the view's size, margins, paddings and layout parameters
    ...
    ViewHolder vh = new ViewHolder(v);
    return vh;
}

// Replace the contents of a view (invoked by the layout manager)
@Override
public void onBindViewHolder(ViewHolder holder, int position) {
    // - get element from your dataset at this position
    // - replace the contents of the view with that element
    holder.mTextView.setText(mDataset[position]);
}

@Override
public int getItemViewType(int position) {
    return super.getItemViewType(position);
}

mRecyclerView = (RecyclerView) findViewById(R.id.my_recycler_view);

  // use this setting to improve performance if you know that changes
  // in content do not change the layout size of the RecyclerView
  mRecyclerView.setHasFixedSize(true);

  // use a linear layout manager
  mLayoutManager = new LinearLayoutManager(this);
  mRecyclerView.setLayoutManager(mLayoutManager);

  // specify an adapter (see also next example)
  mAdapter = new MyAdapter(myDataset);
  mRecyclerView.setAdapter(mAdapter);