如何在android中从recyclerview下面的服务器获取数据

我正试图让显示更多数据如下recyclerview像无休止的滚动，问题是，首先我想在Act onCreate中从url获取数据，然后再次向下滚动时发送请求并从服务器获取数据，但数据不低于5个数据，这是我之前获取的数据，而不是下面的数据删除以前的数据，然后再过来，请帮帮我

 public class MainActivity extends AppCompatActivity {

    public static String m_DealListingURL = "http://192.163.0.110:8080/ireward/rest/json/metallica/getDealListInJSON";
    public CJsonsResponse m_oJsonsResponse;
    public String s_szresult = "";
    private Toolbar mToolbar;
    private RecyclerView mRecyclerView;
    private List<User> mUsers;
    private UserAdapter mUserAdapter;

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

        mToolbar = (Toolbar) findViewById(R.id.toolbar);
        mToolbar.setTitle("LoadMoreRecycleView");
        mUsers = new ArrayList<User>();

        new CDealDataSent().execute(m_DealListingURL);

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

        mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
        mUserAdapter = new UserAdapter();
        mRecyclerView.setAdapter(mUserAdapter);

        mUserAdapter.setOnLoadMoreListener(new OnLoadMoreListener() {
            @Override
            public void onLoadMore() {
                Log.e("haint", "Load More");
                mUsers.add(null);
                mUserAdapter.notifyItemInserted(mUsers.size() - 1);

                //Load more data for reyclerview
                new Handler().postDelayed(new Runnable() {
                    @Override
                    public void run() {
                        Log.e("haint", "Load More 2");

                        //Remove loading item
                        mUsers.remove(mUsers.size() - 1);
                        mUserAdapter.notifyItemRemoved(mUsers.size());

                        new CDealDataSent().execute(m_DealListingURL);
                    }
                }, 5000);
            }
        });
    }

    //sending deal data to retreive response from server
    public String DealListing(String url, CRegistrationDataStorage login) {
        InputStream inputStream = null;
        m_oJsonsResponse = new CJsonsResponse();
        try {
            // 1. create HttpClient
            HttpClient httpclient = new DefaultHttpClient();
            // 2. make POST request to the given URL
            HttpPost httpPost = new HttpPost(url);
            String json = "";
            // 3. build jsonObject
            JSONObject jsonObject = new JSONObject();
            jsonObject.put("agentCode", "9555517491");
            jsonObject.put("pin", "05E0901648FD6439207FA74FC3E07734");
            jsonObject.put("recordcount", "5");
            jsonObject.put("lastcountvalue", "0");
            //jsonObject.put("emailId", "nirajk1190@gmail.com");
            // 4. convert JSONObject to JSON to String
            json = jsonObject.toString();
            // 5. set json to StringEntity
            StringEntity se = new StringEntity(json);
            // 6. set httpPost Entity
            httpPost.setEntity(se);
            // 7. Set some headers to inform server about the type of the content
            httpPost.setHeader("Content-type", "application/json");
            // 8. Execute POST request to the given URL
            HttpResponse httpResponse = httpclient.execute(httpPost);
            HttpEntity entity = httpResponse.getEntity();
            // 9. receive response as inputStream
            inputStream = entity.getContent();
            System.out.println("InputStream....:" + inputStream.toString());
            System.out.println("Response....:" + httpResponse.toString());

            StatusLine statusLine = httpResponse.getStatusLine();
            System.out.println("statusLine......:" + statusLine.toString());
            ////Log.d("resp_body", resp_body.toString());
            int statusCode = statusLine.getStatusCode();
            // 10. convert inputstream to string
            if (statusCode == 200) {
                // 10. convert inputstream to string
                if (inputStream != null)
                    s_szresult = m_oJsonsResponse.convertInputStreamToString(inputStream);
                //String resp_body =
                EntityUtils.toString(httpResponse.getEntity());
            } else
                s_szresult = "Did not work!";
        } catch (Exception e) {
            Log.d("InputStream", e.getLocalizedMessage());
        }
        System.out.println("resul.....:" + s_szresult);
        // 11. return s_szResult
        return s_szresult;
    }

    static class UserViewHolder extends RecyclerView.ViewHolder {
        public TextView tvName;
        public TextView tvEmailId;

        public UserViewHolder(View itemView) {
            super(itemView);
            tvName = (TextView) itemView.findViewById(R.id.tvName);

            tvEmailId = (TextView) itemView.findViewById(R.id.tvEmailId);
        }
    }

    static class LoadingViewHolder extends RecyclerView.ViewHolder {
        public ProgressBar progressBar;

        public LoadingViewHolder(View itemView) {
            super(itemView);
            progressBar = (ProgressBar) itemView.findViewById(R.id.progressBar1);
        }
    }

    //  sending deal data to server and retreive response......
    class CDealDataSent extends AsyncTask<String, Void, String> {
        public JSONObject m_oResponseobject;
        public ProgressDialog m_PDialog;
        public CRegistrationDataStorage oRegisterStorage;
        public User item;

        //      @Override
        protected void onPreExecute() {
            super.onPreExecute();
            m_PDialog = new ProgressDialog(MainActivity.this);
            m_PDialog.setMessage("Please wait while Loading Deals...");
            m_PDialog.setCancelable(false);
            m_PDialog.show();
        }

        @Override
        protected String doInBackground(String... urls) {
            return DealListing(urls[0], oRegisterStorage);// sending data to server...

        }

        // onPostExecute displays the results of the AsyncTask.
        @Override
        protected void onPostExecute(String result) {

            m_PDialog.dismiss();
            try {
                m_oResponseobject = new JSONObject(result);// getting response from server
                final JSONArray posts = m_oResponseobject.optJSONArray("dealList");

                mUsers = new ArrayList<User>();
                for (int i = 0; i < posts.length(); i++) {
                    JSONObject post = posts.getJSONObject(i);
                    item = new User();
                    item.setName(post.getString("dealname"));
                    item.setEmail(post.getString("dealcode"));
                    mUsers.add(item);
                }
                getResponse();

            } catch (JSONException e) {
                e.printStackTrace();
            }
        }

        public void getResponse() throws JSONException {
            if (m_oResponseobject.getString("resultdescription").equalsIgnoreCase("Transaction Successful")) {

                mUserAdapter = new UserAdapter();//creating object of adapter and addd setting odata to adapter for use.
                mRecyclerView.setAdapter(mUserAdapter);//adding adapter to recyclerview
            } else if (m_oResponseobject.getString("resultdescription").equalsIgnoreCase("Connection Not Available")) {
                Toast.makeText(MainActivity.this, "Connection not avaliable", Toast.LENGTH_SHORT).show();
            }

        }

    }

    class UserAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {

        private final int VIEW_TYPE_ITEM = 0;
        private final int VIEW_TYPE_LOADING = 1;

        private OnLoadMoreListener mOnLoadMoreListener;

        private boolean isLoading;
        private int visibleThreshold = 5;
        private int lastVisibleItem, totalItemCount;

        public UserAdapter() {
            final LinearLayoutManager linearLayoutManager = (LinearLayoutManager) mRecyclerView.getLayoutManager();
            mRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
                @Override
                public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
                    super.onScrolled(recyclerView, dx, dy);

                    totalItemCount = linearLayoutManager.getItemCount();
                    lastVisibleItem = linearLayoutManager.findLastVisibleItemPosition();

                    if (!isLoading && totalItemCount <= (lastVisibleItem + visibleThreshold)) {
                        if (mOnLoadMoreListener != null) {
                            mOnLoadMoreListener.onLoadMore();
                        }
                        isLoading = true;
                    }
                }
            });
        }

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

        @Override
        public int getItemViewType(int position) {
            return mUsers.get(position) == null ? VIEW_TYPE_LOADING : VIEW_TYPE_ITEM;
        }

        @Override
        public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
            if (viewType == VIEW_TYPE_ITEM) {
                View view = LayoutInflater.from(MainActivity.this).inflate(R.layout.layout_user_item, parent, false);
                return new UserViewHolder(view);
            } else if (viewType == VIEW_TYPE_LOADING) {
                View view = LayoutInflater.from(MainActivity.this).inflate(R.layout.layout_loading_item, parent, false);
                return new LoadingViewHolder(view);
            }
            return null;
        }

        @Override
        public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
            if (holder instanceof UserViewHolder) {
                User user = mUsers.get(position);
                UserViewHolder userViewHolder = (UserViewHolder) holder;
                userViewHolder.tvName.setText(user.getName());
                userViewHolder.tvEmailId.setText(user.getEmail());
            } else if (holder instanceof LoadingViewHolder) {
                LoadingViewHolder loadingViewHolder = (LoadingViewHolder) holder;
                loadingViewHolder.progressBar.setIndeterminate(true);
            }
        }

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

        public void setLoaded() {
            isLoading = false;
        }
    }
}

public类MainActivity扩展了AppCompatActivity{
公共静态字符串m_DealListingURL=”http://192.163.0.110:8080/ireward/rest/json/metallica/getDealListInJSON";
公共CJsonsResponse m_OJSONS Response；
公共字符串s_szresult=“”；
私有工具栏mToolbar；
私人回收视图mRecyclerView；
私人博物馆名单；
专用用户适配器；
@凌驾
创建时受保护的void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.activity_main）；
mToolbar=（工具栏）findviewbyd（R.id.Toolbar）；
mToolbar.setTitle（“LoadMoreRecycleView”）；
mUsers=newarraylist（）；
新建CDealDataSent（）.execute（m_DealListingURL）；
mRecyclerView=（RecyclerView）findViewById（R.id.recycleView）；
mRecyclerView.setLayoutManager（新的LinearLayoutManager（this））；
mUserAdapter=newuseradapter（）；
mrecycerview.setAdapter（mUserAdapter）；
setOnLoadMoreListener（新的OnLoadMoreListener（））{
@凌驾
public void onLoadMore（）{
Log.e（“haint”，“加载更多”）；
添加（空）；
mUserAdapter.notifyItemInserted（mUsers.size（）-1）；
//为ReyclView加载更多数据
new Handler（）.postDelayed（new Runnable（））{
@凌驾
公开募捐{
Log.e（“haint”，“加载更多2”）；
//删除加载项
移除（mUsers.size（）-1）；
mUserAdapter.notifyItemRemoved（mUsers.size（））；
新建CDealDataSent（）.execute（m_DealListingURL）；
}
}, 5000);
}
});
}
//正在发送交易数据以从服务器检索响应
公共字符串DealListing（字符串url、凭据数据存储登录）{
InputStream InputStream=null；
m_oJsonsResponse=新的CJsonsResponse（）；
试一试{
//1.创建HttpClient
HttpClient HttpClient=新的DefaultHttpClient（）；
//2.向给定URL发出POST请求
HttpPost HttpPost=新的HttpPost（url）；
字符串json=“”；
//3.构建jsonObject
JSONObject JSONObject=新的JSONObject（）；
jsonObject.put（“代理代码”，“9555517491”）；
jsonObject.put（“pin”，“05E0901648FD6439207FA74FC3E07734”）；
jsonObject.put（“记录计数”，“5”）；
jsonObject.put（“lastcountvalue”，“0”）；
//jsonObject.put（“emailId”nirajk1190@gmail.com");
//4.将JSONObject转换为JSON转换为字符串
json=jsonObject.toString（）；
//5.将json设置为StringEntity
StringEntity se=新的StringEntity（json）；
//6.设置httpPost实体
httpPost.setEntity（se）；
//7.设置一些标题以通知服务器内容的类型
setHeader（“内容类型”、“应用程序/json”）；
//8.对给定URL执行POST请求
HttpResponse HttpResponse=httpclient.execute（httpPost）；
HttpEntity entity=httpResponse.getEntity（）；
//9.将响应作为inputStream接收
inputStream=entity.getContent（）；
System.out.println（“InputStream…”：“+InputStream.toString（））；
System.out.println（“响应：”+httpResponse.toString（））；
StatusLine StatusLine=httpResponse.getStatusLine（）；
System.out.println（“statusLine……”：“+statusLine.toString（））；
////Log.d（“resp_body”，resp_body.toString（））；
int statusCode=statusLine.getStatusCode（）；
//10.将inputstream转换为字符串
如果（状态代码==200）{
//10.将inputstream转换为字符串
如果（inputStream！=null）
s_szresult=m_oJsonsResponse.convertInputStreamToString（inputStream）；
//字符串响应体=
toString（httpResponse.getEntity（））；
}否则
s_szresult=“不起作用！”；
}捕获（例外e）{
d（“InputStream”，例如getLocalizedMessage（））；
}
System.out.println（“结果…：”+s_szresult）；
//11.返回s_szResult
返回s_szresult；
}
静态类UserViewHolder扩展了RecyclerView.ViewHolder{
公共文本视图tvName；
公共文本视图TVMailID；
公共用户视图持有者（视图项视图）{
超级（项目视图）；
tvName=（TextView）itemView.findViewById（R.id.tvName）；
TveEmailId=（TextView）itemView.findViewById（R.id.TveEmailId）；
}
}
静态类加载ViewHolder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.progressBar1）；
}
}
//正在将交易数据发送到服务器并检索响应。。。。。。
类CDealDataSent扩展了AsyncTask{
公共JSONObject m_或响应对象；
公共进步对话；
公共凭证登记数据存储或登记存储；
公共用户项目；
//@覆盖
受保护的void onPreExecute（）{
super.onPreExecute（）；
m_PDialog=新建进度对话框（MainActivity.this）；
m_PDialog.setMessage（“请
 mUsers.remove(mUsers.size() - 1);
 mUserAdapter.notifyItemRemoved(mUsers.size());

protected void onPostExecute(String result) {

    m_PDialog.dismiss();
    try {
        m_oResponseobject = new JSONObject(result);// getting response from server
        if(m_oResponseobject.getString("resultdescription").equalsIgnoreCase("Deal List Not Found"))
              return;
        final JSONArray posts = m_oResponseobject.optJSONArray("dealList");
        if(isFirstTime) {
        mUsers = new ArrayList<User>();
        isFirstTime = false;
        } else {
        mUsers.remove(mUsers.size() - 1);
        mUserAdapter.notifyItemRemoved(mUsers.size());
        }
        for (int i = 0; i < posts.length(); i++) {
            JSONObject post = posts.getJSONObject(i);
            item = new User();
            item.setName(post.getString("dealname"));
            item.setEmail(post.getString("dealcode"));
            mUsers.add(item);
            mUserAdapter.notifyItemInserted(mUsers.size());
        }
    } catch (JSONException e) {
        e.printStackTrace();
    }
}