@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.img = (ImageView) rowView.findViewById(R.id.image);
    holder.tv.setText(result[position]);
    holder.img.setImageResource(imageId[position]);
    rowView.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            Toast.makeText(context, "You Clicked " + result[position], Toast.LENGTH_LONG).show();
        }
    });
    return rowView;
}

Holder holder = new Holder();
View rowView = inflater.inflate(R.layout.item_list, null);

@Override
public View getView(final int position, View convertView, ViewGroup parent) {
    // 최초에 convertView가 null이므로, inflate를 처리한다
    if (convertView == null) {
        // 전역으로 생성한 View에 inflate
        rootView = inflater.inflate(R.layout.item_list, null);

        // ViewHolder을 생성
        Holder holder = new Holder();
        holder.tv = (TextView) rowView.findViewById(R.id.text);
        holder.img = (ImageView) rowView.findViewById(R.id.image);

        // setTag
        rootView.setTag(viewHolder);
    } else {
        // convertView에 convertView를 셋팅
        rootView = convertView;
        // rootView에서 holder을 꺼내온다
        holder = (Holder) rootView.getTag();
    }

    holder.tv.setText(result[position]);
    holder.img.setImageResource(imageId[position]);
    rowView.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            Toast.makeText(context, "You Clicked " + result[position], Toast.LENGTH_LONG).show();
        }
    });
    return rootView;
}

@Override
public void loadGitHubUser(String userKeyword) {
    // 마지막 페이지인지 체크
    if (page > 0 && isLastItem) {
        return;
    }

    // Progress 보여주기
    view.showProgress();

    // github를 통해서 User 정보를 받아옵니다.
    final Call<GitHubUserResponse> gitHubUserCall = retrofitGitHub.searchGitHubUser(userKeyword, ++page, DEFAULT_ITEM_COUNT);

    // Retrofit의 enqueue을 통해서 다음을 처리합니다.
    gitHubUserCall.enqueue(new Callback<GitHubUserResponse>() {

        // 성공적인 response을 받았을 경우
        @Override
        public void onResponse(Call<GitHubUserResponse> call, Response<GitHubUserResponse> response) {
            // API limit으로 인해 실패하는 경우가 생깁니다.
            if (!response.isSuccessful()) {
                view.hideProgress();

                /*
                 * API rate limit exceeded for IP Address.
                 * (But here's the good news: Authenticated requests get a higher rate limit. Check out the documentation for more details.)
                 */
                isLastItem = true;
                return;
            }

            // Retrofit에서 GSON을 GitHubUserReponse로 변환한 결과를 받아온다
            GitHubUserResponse gitHubUserResponse = response.body();
            if (gitHubUserResponse != null) {
                if (gitHubUserResponse.items != null && gitHubUserResponse.items.size() > 0) {
                    // items를 추가한다
                    for (GitHubItem item : gitHubUserResponse.items) {
                        view.addItem(item);
                    }
                }
            }

            view.hideProgress();
            view.notifyListView();
        }

        // 받아오기 실패할 경우
        @Override
        public void onFailure(Call<GitHubUserResponse> call, Throwable t) {
            view.hideProgress();
            view.showFailLoad();
        }
    });
}

private class ViewHolder {
    ImageView imgUserAvater;
    TextView tvUserName;
    TextView tvUserScore;
}

@NonNull
@Override
public View getView(int position, View convertView, ViewGroup parent) {
    if (convertView == null) {
        LayoutInflater inflater = LayoutInflater.from(getContext());
        rootView = inflater.inflate(R.layout.item_github_user, parent, false);

        viewHolder = new ViewHolder();
        viewHolder.imgUserAvater = (ImageView) rootView.findViewById(R.id.img_user_avater);
        viewHolder.tvUserName = (TextView) rootView.findViewById(R.id.tv_user_name);
        viewHolder.tvUserScore = (TextView) rootView.findViewById(R.id.tv_user_score);

        // setTag
        rootView.setTag(viewHolder);

    } else {
        rootView = convertView;
        viewHolder = (ViewHolder) rootView.getTag();
    }

    // Holder에 아이템을 출력합니다.
    final GitHubItem gitHubItem = getItem(position);
    if (gitHubItem != null) {
        viewHolder.tvUserName.setText(gitHubItem.login);
        viewHolder.tvUserScore.setText(String.format("%f", gitHubItem.score));

        // ImageDownloadThread을 직접 구현하였습니다.
        ImageDownloadThread.getInstance().loadImage(R.mipmap.ic_launcher, viewHolder.imgUserAvater, gitHubItem.avatar_url);
    }

    return rootView;
}

private class DownloadThread implements Runnable {

  // 생략...

  @Override
  public void run() {
      try {
          URL url = new URL(resourceUrl);
          connection = url.openConnection();
          connection.connect();

          inputStream = connection.getInputStream();
          bufferedInputStream = new BufferedInputStream(inputStream);

          cache.put(resourceUrl, new WeakReference<>(BitmapFactory.decodeStream(bufferedInputStream)));
          draw(resourceUrl);

      } catch (IOException e) {
          closeStream();

      } finally {
          closeStream();
      }
  }

  // 생략 ...

  // Bitmap을 통해 이미지를 그린다. 현재 보여지는 아이템의 위치에 맞게 그리도록 TAG를 활용
  private void draw(final String resourceUrl) {
      new Handler(Looper.getMainLooper()).post(new Runnable() {
          @Override
          public void run() {
              ImageView imageView = weakReferenceImageView.get();
              if (!TextUtils.isEmpty(resourceUrl) &&
                      imageView.getTag() != null &&
                      imageView.getTag().equals(resourceUrl) &&
                      cache.get(resourceUrl) != null &&
                      cache.get(resourceUrl).get() != null) {
                  imageView.setImageBitmap(cache.get(resourceUrl).get());
              }
          }
      });
  }
}

public class RetrofitCreator {

    public static Retrofit createRetrofit() {

        HttpLoggingInterceptor interceptor = new HttpLoggingInterceptor();
        interceptor.setLevel(HttpLoggingInterceptor.Level.BODY);
        OkHttpClient client = new OkHttpClient.Builder().addInterceptor(interceptor).build();

        return new Retrofit.Builder()
                .baseUrl("https://api.github.com/")
                .client(client)
                // Json 변환
                .addConverterFactory(GsonConverterFactory.create())
                .build();
    }
}

CustomTabsIntent.Builder builder = new CustomTabsIntent.Builder();
builder.setToolbarColor(getResources().getColor(R.color.colorPrimary));

builder.setStartAnimations(this, 0, 0);
builder.setExitAnimations(this, 0, 0);

CustomTabsIntent customTabsIntent = builder.build();
customTabsIntent.launchUrl(this, Uri.parse(item.html_url));