Android 带有Asynctask的无尽RecyclerView

我有一个应用程序，它有无尽的recyclerView（当到达列表末尾的某个偏移量时，我从recyclerView适配器调用接口方法）。
回收视图适配器

public SearchResultAdapter(ArrayList<String> suggestions) {
    this.suggestions = suggestions;
}

public SearchResultAdapter(ArrayList<Word> results, RecyclerView recyclerView) {
    words = results;
    this.recyclerView = recyclerView;
    final LinearLayoutManager mLayoutManager = (LinearLayoutManager) recyclerView.getLayoutManager();
    recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
        @Override
        public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
            super.onScrolled(recyclerView, dx, dy);
            if (dy > 0) //check for scroll down
            {
                visibleItemCount = mLayoutManager.getChildCount();
                totalItemCount = mLayoutManager.getItemCount();
                pastVisiblesItems = mLayoutManager.findFirstVisibleItemPosition();
                if (loading) {
                    if ((visibleItemCount + pastVisiblesItems + 14) >= totalItemCount) {
                        if (mOnLoadMoreListener != null)
                            mOnLoadMoreListener.onLoadMore();
                        loading = false;
                    }
                }
            }
        }
    });
}

public void setOnLoadMoreListener(OnLoadMoreListener mOnLoadMoreListener) {
    this.mOnLoadMoreListener = mOnLoadMoreListener;
}

public void setOnSearchResultClickListener(OnSearchResultClickListener mClickListener) {
    this.mClickListener = mClickListener;
}

public void setLoading() {
    loading = true;
}

@Override
public int getItemViewType(int position) {
   if(words !=null)
       return words.get(position) == null ? VIEW_TYPE_LOADING : VIEW_TYPE_ITEM;
    else 
       return VIEW_TYPE_SUGGESTION;
}

@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    Context context = parent.getContext();
    LayoutInflater inflater = LayoutInflater.from(context);
    if (suggestions != null) {
        View view = inflater.inflate(R.layout.activity_suggestion_item, parent, false);
        return new SuggestionsViewHolder(view);
    }
    if (words != null) {
        // Inflate the custom layout
        if (viewType == VIEW_TYPE_ITEM) {
            View view = inflater.inflate(R.layout.activity_main_search_result_item, parent, false);
            return new WordViewHolder(view);
        }
        //inflate loading
        else if (viewType == VIEW_TYPE_LOADING) {
            View view = inflater.inflate(R.layout.activity_main_search_result_loading, parent, false);
            return new LoadingViewHolder(view);
        }
    }
    return null;
}

@Override
public void onBindViewHolder(RecyclerView.ViewHolder viewHolder, int position) {
    Word word=null;
    if(words !=null)
    word = words.get(position);
    if (viewHolder instanceof LoadingViewHolder) {
        LoadingViewHolder holder = (LoadingViewHolder) viewHolder;
        holder.progressBar.setIndeterminate(true);
    } else if (viewHolder instanceof WordViewHolder) {
        WordViewHolder holder = (WordViewHolder) viewHolder;
        holder.wordTextView.setText(word.getTitle());
        holder.sourceTextView.setText(word.getSource().getTitle());
    } else if (viewHolder instanceof SuggestionsViewHolder){
        SuggestionsViewHolder holder = (SuggestionsViewHolder) viewHolder;
        holder.wordTextView.setText(suggestions.get(position));
    }
    //wordTextView.loadDataWithBaseURL(null,result.toString(), "text/html", "utf-8", null);
}

@Override
public int getItemCount() {
    return words == null ? (suggestions ==null?0:suggestions.size()) : words.size();
}

public static class LoadingViewHolder extends RecyclerView.ViewHolder {
    public ProgressBar progressBar;
    public LoadingViewHolder(View itemView) {
        super(itemView);
        progressBar = (ProgressBar) itemView.findViewById(R.id.search_item_progressbar);
    }
}

public class WordViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
    // public TextView titleTextView;
    private CustomTextView wordTextView;
    private CustomTextView sourceTextView;
    private CardView searchResultItem;
    public WordViewHolder(View itemView) {
        super(itemView);
        searchResultItem = (CardView) itemView.findViewById(R.id.search_result_item_cardview);
        wordTextView = (CustomTextView) itemView.findViewById(R.id.search_result_item_body);
        sourceTextView = (CustomTextView) itemView.findViewById(R.id.search_result_source);
        searchResultItem.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
       mClickListener.onSearchResultClick(getAdapterPosition());
    }
}

public class SuggestionsViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener{
    // public TextView titleTextView;
    private CustomTextView wordTextView;
    private CardView suggestionItem;
    public SuggestionsViewHolder(View itemView) {
        super(itemView);
        suggestionItem = (CardView) itemView.findViewById(R.id.suggestion_item_cardview);
        wordTextView = (CustomTextView) itemView.findViewById(R.id.activity_suggestion_title);
        wordTextView.setTypeface(MainActivity.custom_font);
        suggestionItem.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
            mClickListener.onSuggestionClick(suggestions.get(getAdapterPosition()));
    }
}
@Override
public int getItemViewType(int position) {
   if(words !=null)
       return words.get(position) == null ? VIEW_TYPE_LOADING : VIEW_TYPE_ITEM;
    else 
       return VIEW_TYPE_SUGGESTION;
}

publicsearchResultAdapter（ArrayList建议）{
这个.建议=建议；
}
公共SearchResultAdapter（ArrayList结果，RecyclerView RecyclerView）{
文字=结果；
this.recyclerView=recyclerView；
最终LinearLayoutManager mLayoutManager=（LinearLayoutManager）recyclerView.getLayoutManager（）；
recyclerView.addOnScrollListener（新的recyclerView.OnScrollListener（）{
@凌驾
已填空的公共空间（RecyclerView RecyclerView、int dx、int dy）{
super.onScrolled（recyclerView、dx、dy）；
如果（dy>0）//检查是否向下滚动
{
visibleItemCount=mLayoutManager.getChildCount（）；
totalItemCount=mLayoutManager.getItemCount（）；
pastVisiblesItems=mLayoutManager.findFirstVisibleItemPosition（）；
如果（装载）{
如果（（visibleItemCount+pastVisiblesItems+14）>=totalItemCount）{
if（mOnLoadMoreListener！=null）
mOnLoadMoreListener.onLoadMore（）；
加载=假；
}
}
}
}
});
}
public void setOnLoadMoreListener（OnLoadMoreListener mOnLoadMoreListener）{
this.mOnLoadMoreListener=mOnLoadMoreListener；
}
公共无效设置SearchResultClickListener（OnSearchResultClickListener mClickListener）{
this.mClickListener=mClickListener；
}
公共无效设置加载（）{
加载=真；
}
@凌驾
public int getItemViewType（int位置）{
如果（字！=null）
返回words.get（position）=null？查看类型\u加载：查看类型\u项；
其他的
返回视图\类型\建议；
}
@凌驾
public RecyclerView.ViewHolder onCreateViewHolder（视图组父级，int-viewType）{
Context=parent.getContext（）；
LayoutFlater充气机=LayoutFlater.from（上下文）；
if（建议！=null）{
视图=充气机。充气（R.layout.activity\u suggestion\u项，父项，false）；
返回新的SuggestionViewHolder（视图）；
}
如果（字！=null）{
//对自定义布局进行充气
if（视图类型==视图类型项目）{
视图=充气机。充气（R.layout.activity\u main\u search\u result\u item，parent，false）；
返回新的WordViewHolder（视图）；
}
//充气装载
else if（viewType==视图类型加载）{
视图=充气机。充气（R.layout.activity\u main\u search\u result\u loading，parent，false）；
返回新的LoadingViewHolder（视图）；
}
}
返回null；
}
@凌驾
BindViewHolder上的公共无效（RecyclerView.ViewHolder ViewHolder，int位置）{
Word=null；
如果（字！=null）
word=words.get（位置）；
if（加载viewHolder的viewHolder实例）{
LoadingViewHolder=（LoadingViewHolder）viewHolder；
holder.progressBar.SetUndeterminate（真）；
}else if（viewHolder实例of WordViewHolder）{
WordViewHolder=（WordViewHolder）viewHolder；
holder.wordTextView.setText（word.getTitle（））；
holder.sourceTextView.setText（word.getSource（）.getTitle（））；
}else if（建议的viewHolder实例viewHolder）{
SuggestionViewHolder=（SuggestionViewHolder）viewHolder；
holder.wordTextView.setText（建议.get（位置））；
}
//wordTextView.loadDataWithBaseURL（null，result.toString（），“text/html”，“utf-8”，null）；
}
@凌驾
public int getItemCount（）{
返回words==null？（建议==null？0:suggestions.size（））：words.size（）；
}
公共静态类LoadingViewHolder扩展了RecyclerView.ViewHolder{
公共ProgressBar ProgressBar；
公共加载视图持有者（视图项视图）{
超级（项目视图）；
progressBar=（progressBar）itemView.findViewById（R.id.search\u item\u progressBar）；
}
}
公共类WordViewHolder扩展了RecyclerView.ViewHolder实现了View.OnClickListener{
//公共文本视图titleTextView；
私有自定义文本视图wordTextView；
私有CustomTextView sourceTextView；
private CardView searchResultItem；
公共WordViewHolder（查看项目视图）{
超级（项目视图）；
searchResultItem=（CardView）itemView.findViewById（R.id.search\u result\u item\u CardView）；
wordTextView=（CustomTextView）itemView.findViewById（R.id.search\u result\u item\u body）；
sourceTextView=（CustomTextView）itemView.findViewById（R.id.search\u result\u source）；
searchResultItem.setOnClickListener（此）；
}
@凌驾
公共void onClick（视图）{
onSearchResultClick（getAdapterPosition（））；
}
}
公共类SuggestionViewHolder扩展了RecyclerView.ViewHolder实现了View.OnClickListener{
//公共文本视图titleTextView；
私有自定义文本视图wordTextView；
private CardView建议项；
公共建议视图持有者（查看项目视图）{
超级（项目视图）；
suggestionItem=（CardView）itemView.findViewById（R.id.suggestion\u item\u CardView）；
wordTextView=（CustomTextView）itemView.findViewById（R.id.activity\u suggestion\u title）；
wordTextView.setTypeface（MainActivity.custom_字体）；
suggestionItem.setOnClickListener（此）；
}
@凌驾
公共void onClick（视图）{
mClickListener.onSuggestionClick（suggestions.get（getAdapterPosition（））；
}
}
@凌驾
public int getItemViewType（int位置）{
如果（字！=null）
返回words.get（position）=null？查看类型\u加载：查看类型\u项；
其他的
返回视图\类型\建议；
}

OnLoadMore

 @Override
public void onLoadMore() {
    if (request.getPage() < totalPageAmount) {
        request.nextPage();
        LoadMoreTask task = new LoadMoreTask(request, words, adapter);
        task.execute();
    }
}

@覆盖
public void onLoadMore（）{
if（request.getPage（） public LoadMoreTask(Request request, ArrayList<Word> words, SearchResultAdapter adapter){
    this.request=request;
    this.words=words;
    this.adapter=adapter;
    this.connection = new Connection(request.getUrl());
}

@Override
protected void onPreExecute() {
    super.onPreExecute();
    if(words.get(words.size()-1)!=null){
        words.add(null);
        index = words.size() - 1;
        adapter.notifyItemInserted(index);
    }
}

@Override
protected Void doInBackground(Void... params) {
    connection.connect();
    String result = connection.getStringFromServer();
    Respond respond = new Respond(result);
    if(!request.isDetailed())
        words.addAll(respond.handleSimple());
    return null;
}

@Override
protected void onPostExecute(Void aVoid) {
    super.onPostExecute(aVoid);
    connection.disconnect();
    if(index!=0 && words.get(index)==null){
        words.remove(index);
        adapter.notifyItemRemoved(index+1);
    }
    adapter.notifyDataSetChanged();
    adapter.setLoading();
}

@Override
protected void onPostExecute(Void aVoid) {
    super.onPostExecute(aVoid);
    connection.disconnect();
    adapter.resetLoading();
    if(index!=0 && words.get(index)==null){
        words.remove(index);
        adapter.notifyItemRemoved(index);
    }
    adapter.notifyItemRangeInserted(index,30);
}