基于数据挖掘的旅游推荐APP（三）：热门景点模块

        该模块数据来源于百度搜索风云榜之今日风景名胜排行榜（链接），通过调用托管在神箭手云上的API接口可以实现数据的实时抓取，可以参考这里。

        效果图：

        接着上一篇继续说，该模块对应LauchFragment，代码如下：

LaunchFragment.java

public class LaunchFragment extends Fragment {

    private static final String TAG="LaunchFragment";
    private RecyclerView mRecyclerView;
    private List mItems= new ArrayList<>(); //这里必须写= new ArrayList<>(),否则可能空指针报错
                        //多线程原因，后台联网下载时，主线程运行，当运行到getItemCount时报错

    public static LaunchFragment newInstance(){
        return new LaunchFragment();
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setRetainInstance(true);
        new FetchItemsTask().execute();
    }

    @Override
    public View onCreateView(LayoutInflater inflater,  ViewGroup container, Bundle savedInstanceState) {
        View v=inflater.inflate(R.layout.fragment_launch,container,false);
        mRecyclerView=(RecyclerView) v.findViewById(R.id.hotspot_recycler_view);
        mRecyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
        setupAdapter();
        return v;
    }

    private void setupAdapter() {
        if (isAdded()) {
            //mItems=new BaiDuTopFetchr().fetchItems();//由于多线程运行，需要先判断fragment是否和activity连接
            mRecyclerView.setAdapter(new HotSpotAdapter(mItems));
        }
    }

    private class HotSpotHolder extends RecyclerView.ViewHolder{
        private TextView mRankTextView;
        private TextView mKeywordTextView;
        private TextView mIndexTextView;
        private HotSpotRankItem mHotSpotRankItem;

        public HotSpotHolder(View itemView) {
            super(itemView);
            mRankTextView=(TextView)itemView.findViewById(R.id.hotspot_rank);
            mKeywordTextView=(TextView)itemView.findViewById(R.id.hotspot_keyword);
            mIndexTextView=(TextView)itemView.findViewById(R.id.hotspot_index);
        }

        public void bindHotSpot(HotSpotRankItem hotspot){
            mRankTextView.setText(hotspot.getRank());
            mKeywordTextView.setText(hotspot.getKeyword());
            mIndexTextView.setText("搜索指数："+hotspot.getIndex());
        }
    }

    private class HotSpotAdapter extends RecyclerView.Adapter{
        private List mHotSpotRankItems;

        public HotSpotAdapter(List hotSpotRankItems) {
            mHotSpotRankItems = hotSpotRankItems;
        }

        @Override
        public HotSpotHolder onCreateViewHolder(ViewGroup parent, int viewType) {
            View view=LayoutInflater.from(getActivity()).inflate(R.layout.list_item_hotspot,parent,false);
            return new HotSpotHolder(view);
        }

        @Override
        public void onBindViewHolder(HotSpotHolder holder, int position) {
            HotSpotRankItem hotspot=mHotSpotRankItems.get(position);
            holder.bindHotSpot(hotspot);
        }

        @Override
        public int getItemCount() {
            return mHotSpotRankItems.size();
        }
    }

    private class FetchItemsTask extends AsyncTask> {
        @Override
        protected List doInBackground(Void... params) {
            Log.i(TAG,"do in back");
            return new BaiDuTopFetchr().fetchItems();
        }

        @Override
        protected void onPostExecute(List hotSpotRankItems) {
            Log.i(TAG,"return otems");
            mItems=hotSpotRankItems;
            setupAdapter();
        }
    }
}

        API调用及返回的json数据解析：

BaiDuTopFetchr.java

public class BaiDuTopFetchr {
    private String mAppid="80b574f8abf4224cee648bb060984015";
    private String mHttpUrl = "http://api.shenjian.io/";
    private String mHttpArg = "appid="+mAppid;

    private static final String TAG = "BaiDuTopFetchr";

    public  String request(String httpUrl, String httpArg) {
        BufferedReader reader=null;
        String result=null;
        StringBuffer sbf=new StringBuffer();
        httpUrl=httpUrl+"?"+httpArg;
        try {
            URL url=new URL(httpUrl);
            HttpURLConnection cOnnection=(HttpURLConnection)url.openConnection();
            connection.setRequestMethod("GET");
            connection.connect();
            InputStream is=connection.getInputStream();
            reader=new BufferedReader(new InputStreamReader(is,"UTF-8"));
            String strRead = null;
            while ((strRead = reader.readLine()) != null) {
                sbf.append(strRead);
                sbf.append("\r\n");
            }
            reader.close();
            result = sbf.toString();
        }
        catch (Exception e) {
            e.printStackTrace();
        }
        return result;
    }

    public List fetchItems() {

        List items = new ArrayList<>();

        try {
            String jsOnString= request(mHttpUrl,mHttpArg);
            Log.i(TAG, "Received JSON: " + jsonString);
            JSONObject jsOnBody= new JSONObject(jsonString);
            parseItems(items, jsonBody);
        } catch (IOException ioe) {
            Log.e(TAG, "Failed to fetch items", ioe);
        } catch (JSONException je) {
            Log.e(TAG, "Failed to parse JSON", je);
        }

        return items;
    }

    private void parseItems(List items, JSONObject jsonBody)
            throws IOException, JSONException {

        JSONArray hotSpotJsOnArray= jsonBody.getJSONArray("data");

        for (int i = 0; i  
 
HotSpotRankItem.java
 
 
public class HotSpotRankItem {
    private String mRank;
    private String mKeyword;
    private String mIndex;

    public String getRank() {
        return mRank;
    }

    public void setRank(String rank) {
        mRank = rank;
    }

    public String getKeyword() {
        return mKeyword;
    }

    public void setKeyword(String keyword) {
        mKeyword = keyword;
    }

    public String getIndex() {
        return mIndex;
    }

    public void setIndex(String index) {
        mIndex = index;
    }

}
 
 
布局文件：
 
 
fragment_launch.xml
 
 

 
 
list_item_hotspot.xml
 
 



        

        

        

源代码在前面博客里。