Convert Android data to JSON to use JSON data for clients and clients

(1) First create the Service,videonewsservicebean that generates the original data, which is an implementation class of an interface, the functions of the interface are as follows:

publicinterface VideoNewsService {    /**     * 获取最新的视频资讯     * @return     */    publicgetLastNews();}

News Category

publicclass News {    private Integer id;    private String title;    private Integer timelength;    publicNews(Integer id, String title, Integer timelength) {        this.id = id;        this.title = title;        this.timelength = timelength;    }    //get/set方法}

Implementation classes for interfaces: generating some false data

 Public  class Videonewsservicebean implements videonewsservice {     PublicList<news>getlastnews() {List<news> Newes =NewArraylist<news> (); Newes.add (NewNews ( -,"Pleasant goat and grey wolf complete", +)); Newes.add (NewNews (Ten,"Real shot ship helicopters in East China Sea Rescue Drill", -)); Newes.add (NewNews ( About,"Cameroon vs Holland", -));returnNewes; }}

(2) Returning data to the client via a servlet: Listservlet.java

 Public  class listservlet extends httpservlet {    Private Static Final LongSerialversionuid =1LPrivateVideonewsservice Service =NewVideonewsservicebean ();protected void Doget(HttpServletRequest request, httpservletresponse response)throwsServletexception, IOException {doPost (request, response); }protected void DoPost(HttpServletRequest request, httpservletresponse response)throwsServletexception, IOException {list<news> videos = service.getlastnews ();//[{id:56,title: "xxxxx", Timelength:90},{id:16,title: "Xbbx", timelength:20}]StringBuilder Builder =NewStringBuilder ();//Append data to JSON formatBuilder.append (' ['); for(News News:videos) {Builder.append (' {'); Builder.append ("ID:"). Append (News.getid ()). Append (', '); Builder.append (" title:\ " "). Append (News.gettitle ()). Append ("\","); Builder.append ("Timelength:"). Append (News.gettimelength ()); Builder.append ("},"); }//Delete last multiple charactersBuilder.deletecharat (Builder.length ()-1); Builder.append ('] ');//Set the data in the request domain, jump to the JSP page when the client requests the servlet, and actually request the JSP pageRequest.setattribute ("JSON", builder.tostring ()); Request.getrequestdispatcher ("/web-inf/page/jsonvideonews.jsp"). Forward (request, response); }}

(3) When the client through the servlet request through the jump can return to the JSP page data (using the El expression, because the JSON data is a string type, so Contenttype= "text/plain; Charset=utf-8 ")

<%@ page language="java" contentType="text/plain; charset=UTF-8" pageEncoding="UTF-8"%>${json}

(4) Extracting data from the client
The same first step is still to create a news class, which omits
Create a Service,videonewsservice.java that gets JSON

 Public  class videonewsservice {    /** * Get the latest video information * @return * @throws Exception */     Public StaticList<news>getjsonlastnews()throwsexception{String Path ="Server requests the address of the servlet"; URL url =NewURL (path);        HttpURLConnection conn = (httpurlconnection) url.openconnection (); Conn.setconnecttimeout ( the); Conn.setrequestmethod ("GET");if(Conn.getresponsecode () = = $) {InputStream instream = Conn.getinputstream ();returnParsejson (instream); }return NULL; }/** * Parse JSON data * @param instream * @return * *    Private StaticList<news>Parsejson(InputStream instream)throwsexception{list<news> newses =NewArraylist<news> ();byte[] data = Streamtool.read (instream); String JSON =NewString (data);//Because the data is similar to the array in the form of repeated use of JsonarrayJsonarray array =NewJsonarray (JSON); for(inti =0; I < Array.Length ();            i++) {Jsonobject jsonobject = Array.getjsonobject (i); News news =NewNews (Jsonobject.getint ("id"), Jsonobject.getstring ("title"), Jsonobject.getint ("Timelength"));        Newses.add (news); }returnnewses; }}

Here, a tool class Streamtool.java is used to stream the input to a byte data return

 Public  class streamtool {    /** * Read input stream data * /     Public Static byte[]Read(InputStream instream)throwsException {Bytearrayoutputstream OutStream =NewBytearrayoutputstream ();byte[] buffer =New byte[1024x768];intLen =0; while(len = instream.read (buffer))! =-1) {outstream.write (buffer,0, Len); } instream.close ();returnOutstream.tobytearray (); }

You can then use the data in a specific interface: (Here is a ListView setting value)
Mainactivity.java

 Public  class mainactivity extends Activity {    /** Called when the activity is first created. * /    @Override     Public void onCreate(Bundle savedinstancestate) {Super. OnCreate (Savedinstancestate);        Setcontentview (R.layout.main); ListView ListView = (ListView) This. Findviewbyid (R.id.listview);Try{list<news> videos = videonewsservice.getjsonlastnews ();//need to modify the HTTP request path to your native computer            //ListlistNewArraylist for(News News:videos) {hashmap<string, object> item =NewHashmap<string, object> (); Item.put ("id", News.getid ()); Item.put ("title", News.gettitle ()); Item.put ("Timelength", Getresources (). getString (r.string.timelength) + news.gettimelength () + getresources (). getString (R.                String.min));            Data.add (item); }//Set the adapter for the ListViewSimpleadapter adapter =NewSimpleadapter ( This, data, R.layout.item,Newstring[]{"title","Timelength"},New int[]{r.id.title, r.id.timelength}];        Listview.setadapter (adapter); }Catch(Exception e)        {E.printstacktrace (); }    }}

The generated guest client to this JSON data uses the JSON data operation to complete!

Convert Android data to JSON to use JSON data for clients and clients