Android ListView Page Load (server side +android) Demo

Android ListView page Loading function is often used in the actual development, is the content that each developer must master, this demo gives the service end of the +android end of the code, and successfully passed the test.

The server uses eclipse with the myeclipse,android-side.

Realize:

The server has a total of 100 data, divided into four pages, each page has 25 data.

Source:

Service side:

You need to import these jar packages in the diagram.

Before running the Android terminal code, you need to open the server:

The following first gives the server code:

Class Empdatasource:

Package Com.android.divpage;import java.util.arraylist;import java.util.list;/** * Server data * @author Administrator * */ public class Empdatasource {list<string> list, public list<string> Getdatasource () {list = new arraylist< String> (); for (int i = 0; i <; i++) {List.add ("Hellonihao" +i);} return list;}}

Devidepage:

Package Com.android.divpage;public class Devidepage {private int pagesize;//the number of bars displayed per page private int recordcount;// Total number of records private int currentpage;//current page private int pagecount;//total pages public devidepage (int pageSize, int recordCount, int curre Ntpage) {this.pagesize = Pagesize;this.recordcount = Recordcount;this.setcurrentpage (currentPage);} public int getpagesize () {return pageSize;} public void setpagesize (int pageSize) {this.pagesize = pageSize;} public int GetRecordCount () {return recordCount;} public void Setrecordcount (int recordCount) {this.recordcount = RecordCount;}  /** * Get total pages */public int Getpagecount () {PageCount = recordcount/pagesize;int mod = recordCount% pagesize;if (mod! = 0) {pagecount++;} return PageCount = = 0? 1:pagecount;} public void Setpagecount (int pagecount) {this.pagecount = PageCount;} public int getcurrentpage () {return currentpage;} /** * Set positioning on the current page */private void setcurrentpage (int currentpage) {int activepage = currentpage <= 0? 1:currentpage;acti Vepage = ActivepagE > Getpagecount ()? Getpagecount (): Activepage;this.currentpage = ActivePage;} public int Getfromindex () {return (currentPage-1) * pageSize;} public int Gettoindex () {return math.min (RecordCount, currentpage * pageSize);}}

Empaction:

Package Com.android.divpage;import Java.io.ioexception;import Java.io.printwriter;import java.util.List;import Javax.servlet.servletexception;import Javax.servlet.http.httpservlet;import Javax.servlet.http.httpservletrequest;import Javax.servlet.http.httpservletresponse;import Net.sf.json.JSONArray ;p ublic class Empaction extends HttpServlet {public void doget (HttpServletRequest request, httpservletresponse response) Throws Servletexception, IOException {this.dopost (request, response);} Jsonarray array = null;public void DoPost (HttpServletRequest request, httpservletresponse response) throws Servletexception, IOException {response.setcontenttype ("Text/html;charset=utf-8"); Request.setcharacterencoding (" Utf-8 "); Response.setcharacterencoding (" Utf-8 "); PrintWriter writer = Response.getwriter (); Empdatasource DataSource = new Empdatasource ();/** * Get data from Empdatasource class */list<string> list = Datasource.getdatasource (); String PageNo = Request.getparameter ("PageNo"); int currentpage = 1;//The current page is the firstPage if (PageNo! = null) {currentpage = Integer.parseint (PageNo);} /** * Page: There are 25 data per page, because there are 100, so there are a total of 4 pages. */devidepage putil = new Devidepage (+ list.size (), currentpage); int start = Putil.getfromindex (); int end = Putil.gettoin Dex (); list<string> sublist = list.sublist (start, end); array = Jsonarray.fromobject (sublist); writer.println (array); Writer.flush (); Writer.close ();}}

Android side;

Layout file:

<relativelayout xmlns:android= "http://schemas.android.com/apk/res/android"    xmlns:tools= "http// Schemas.android.com/tools "    android:layout_width=" match_parent "    android:layout_height=" Match_parent "    android:paddingbottom= "@dimen/activity_vertical_margin"    android:paddingleft= "@dimen/activity_ Horizontal_margin "    android:paddingright=" @dimen/activity_horizontal_margin "    android:paddingtop=" @dimen /activity_vertical_margin "    tools:context=". Mainactivity ">    <listview        android:id=" @+id/listview "        android:layout_width=" Match_parent "        android:layout_height= "match_parent"        android:layout_alignparenttop= "true"        android:layout_ Centerhorizontal= "true" >    </ListView></RelativeLayout>

Mainactivity:

Remember to change the IP address in the path to your own native IP address.

Package Com.listviewdemo_divpage;import Java.io.bufferedreader;import Java.io.inputstream;import Java.io.inputstreamreader;import Java.util.arraylist;import Java.util.list;import Org.apache.http.HttpResponse; Import Org.apache.http.client.httpclient;import Org.apache.http.client.methods.httpget;import Org.apache.http.impl.client.defaulthttpclient;import Org.json.jsonarray;import Org.json.JSONException;import Android.app.activity;import Android.app.progressdialog;import Android.os.asynctask;import Android.os.Bundle; Import Android.view.view;import Android.view.viewgroup;import Android.widget.abslistview;import Android.widget.abslistview.onscrolllistener;import Android.widget.baseadapter;import Android.widget.ListView; Import Android.widget.textview;import Android.widget.toast;public class Mainactivity extends Activity {private String Emp_path = "http://172.16.17.36:8080/JsonServiceDemo/servlet/EmpAction?pageNo=";p rivate ListView listview;private Myadapter Adapter;private Boolean Is_divpage;//Whether to do paging operation private list<string> onetotal = new arraylist<string> ();//For storing a page of data private list<string> Total = new arraylist<string> ();//used to store all data obtained private progressdialog dialog;private static int pageno = 1;// Set the initialization value of PageNo to 1, which is the first page of data obtained by default. @Overrideprotected void OnCreate (Bundle savedinstancestate) {super.oncreate (savedinstancestate); Setcontentview ( R.layout.activity_main); listview = (ListView) Findviewbyid (r.id.listview);d ialog = new ProgressDialog ( Mainactivity.this);d ialog.settitle ("Warning");d ialog.setmessage ("Loading information ..."); adapter = new Myadapter ();/** * used to get data ... */ New MyTask (). Execute (emp_path + pageno); Listview.setonscrolllistener (new Onscrolllistener () {@Overridepublic void Onscrollstatechanged (abslistview view, int scrollstate) {/** * When paging operation Is_divpage true, sliding stop, and pageno<= 4 (here because the server has 4 pages of data), load more data. */if (is_divpage && scrollstate = = Onscrolllistener.scroll_state_idle && pageno <=4) {Toast.maketext (Mainactivity.this, "getting more data ...", toast.length_shORT). Show (); new MyTask (). Execute (emp_path+pageno);} else if (PageNo >4) {/** * If pageno>4 indicates that there is no more data on the server to load. */toast.maketext (Mainactivity.this, "No more data ...", Toast.length_short). Show ();}} /** * When: the first visible item (FIRSTVISIBLEITEM) + the number of visible items (visibleitemcount) = ALL item Total, * Is_divpage becomes true, this time the data is loaded. */@Overridepublic void onscroll (abslistview view, int firstvisibleitem,int visibleitemcount, int totalitemcount) {Is_ Divpage = (Firstvisibleitem + visibleitemcount = = Totalitemcount);}});} /** * MyTask inheritance thread pool Asynctask used for network data requests, JSON parsing, data update and other operations. */class MyTask extends Asynctask<string, Void, string> {/** * Data request before display dialog. */@Overrideprotected void OnPreExecute () {super.onpreexecute ();d ialog.show ();} /** * In the Doinbackground method, do some time-consuming operations such as network requests. */@Overrideprotected string Doinbackground (String ... params) {return RequestData ();} /** * In this method, the main processing of some data, update. */@Overrideprotected void OnPostExecute (String result) {Super.onpostexecute (result); if (result! = NULL) {// If the result data obtained is not NULL, it is parsed by JSON. and displayed inOn the phone screen. list<string> list = jsonanalysis (result); Total.addall (list); Adapter.binddata (total);/** * When PageNo equals 1, it will be setadapter, will not be set again, direct notifydatasetchanged, to update the data *, so as to avoid each load more data, will be back to the first page. */if (PageNo = = 1) {Listview.setadapter (adapter);} Adapter.notifydatasetchanged ();p ageno++;} else if (result = = null) {Toast.maketext (mainactivity.this, "Request data Failed ...", Toast.length_long). Show (); Dialog.dismiss ();}} /** * The adapter for the ListView */class Myadapter extends Baseadapter {list<string> list;/** * Binddata is used to pass data to the adapter. * @param list */public void Binddata (list<string> list) {this.list = list;} @Overridepublic int GetCount () {return list.size ();} @Overridepublic Object getItem (int position) {return list.get (position);} @Overridepublic long Getitemid (int position) {return position;} @Overridepublic view GetView (int position, view Convertview, ViewGroup parent) {TextView TextView = null;if (Convertview = = null) {TextView = new TextView (mainactivity.this);} else {TextView = (TextView) CONVERTVIEW;} Textview.settextsize (Textview.settext); List.get (position); return textView;}} /** * Network data request * @return */public String RequestData () {HttpGet get = new HttpGet (Emp_path+pageno); HttpClient client = new Defaulthttpclient (); StringBuilder Builder = null;try {HttpResponse response = Client.execute (GET), if (Response.getstatusline (). Getstatuscode () = = () {InputStream InputStream = response.getentity (). getcontent (); BufferedReader reader = new BufferedReader (new InputStreamReader (InputStream)); builder = new StringBuilder (); String s = null;for (s = reader.readline (); s = null; s = Reader.readline ()) {builder.append (s);}}} catch (Exception e) {e.printstacktrace ();} return builder.tostring ();} /** * JSON parsing * @param result * @return */public list<string> jsonanalysis (String result) {onetotal.clear ();//first clear before parsing To ensure that only the data on the page is stored and avoid duplication. Jsonarray array = null;try {array = new Jsonarray (result);} catch (Jsonexception e) {e.printstacktrace ();} try {String str0 = array.getstring (0); String str1 = arrAy.getstring (1); String str2 = array.getstring (2); String STR3 = array.getstring (3); String STR4 = array.getstring (4); String STR5 = array.getstring (5); String STR6 = array.getstring (6); String STR7 = array.getstring (7); String str8 = array.getstring (8); String STR9 = array.getstring (9); String str10 = array.getstring (10); String Str11 = array.getstring (11); String str12 = array.getstring (12); String Str13 = array.getstring (13); String str14 = array.getstring (14); String str15 = array.getstring (15); String str16 = array.getstring (16); String str17 = array.getstring (17); String str18 = array.getstring (18); String str19 = array.getstring (19); String Str20 = array.getstring (20); String Str21 = array.getstring (21); String str22 = array.getstring (22); String str23 = array.getstring (23); String str24 = array.getstring; Onetotal.add (STR0); Onetotal.add (str1); Onetotal.add (str2); Onetotal.add (STR3); o Netotal.add (STR4); Onetotal.add (STR5); Onetotal.add (STR6); Onetotal.add (STR7); Onetotal.add (STR8); Onetotal.add ( STR9); OnetoTal.add (STR10); Onetotal.add (STR11); Onetotal.add (str12); Onetotal.add (Str13); Onetotal.add (Str14); Onetotal.add ( STR15); Onetotal.add (str16); Onetotal.add (str17); Onetotal.add (str18); Onetotal.add (STR19); Onetotal.add (STR20); o Netotal.add (STR21); Onetotal.add (STR22); Onetotal.add (Str23); Onetotal.add (STR24);} catch (Jsonexception e) {e.printstacktrace ();} Return onetotal;//only returns the data for this page}}

Remember to add network permissions in the Manifest.xml file.

Source code Download:

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