Android gets JSON parsing from server to display on client

Android getting JSON parsing from the server is displayed on the client

Baidu Experience: jingyan.baidu.com

First of all, the most basic characteristics of JSON data, JSON data is a series of key-value pairs of the collection, and XML data, the size of the JSON data is smaller, high transmission efficiency, easy to parse, but the readability is not high;

Because this time to get the JSON data from the server side, and after parsing the parsed data displayed in the Android client, first deploy the server-side code (directly using Jsp/servlet):

The JSON data is constructed as follows:

[{"Name": "Zhang San", "Address": "Beijing", "Age": 20},{"name": "John Doe", "Address": "Shanghai", "Age": 30},{"name": "Harry", "Address": "Shenzhen", "Age" : 35}]

[One] server side (Person.java omitted):

①: Data Construction Jsonservice.java

public class Jsonservice {

public static list<person> Getlistperson () {

list<person> mlists = new arraylist<person> ();

Mlists.add (New person ("Zhang San", "Beijing", 20));

Mlists.add (New person ("John Doe", "Shanghai", 30));

Mlists.add (New person ("Harry", "Shenzhen", 35));

return mlists;

}

②:servlet code (including the construction of JSON data, no JSON data conversion method is used) Jsonservlet.java

public void doget (HttpServletRequest request, httpservletresponse response)

Throws Servletexception, IOException {

Response.setcontenttype ("text/html");

Response.setcharacterencoding ("UTF-8");

PrintWriter out = Response.getwriter ();

list<person> persons = Jsonservice.getlistperson ();

StringBuffer sb = new StringBuffer ();

Sb.append (' [');

for (person Person:persons) {

Sb.append (' {'). Append ("\" name\ ":"). Append ("\" "+person.getname () +" \ ""). Append (","); Sb.append ("\" address\ ":"). Append ("\" "+person.getaddress () +" \ ""). Append (",");

Sb.append ("\" age\ ":"). Append (Person.getage ());

Sb.append ('} '). Append (",");

}

Sb.deletecharat (Sb.length ()-1);

Sb.append ('] ');

Out.write (New String (SB));

Out.flush ();

Out.close ();

}

③: Deployment to tomact Browser input Http://localhost/JsonWeb/JsonServlet Direct access results are as follows:

[{"Name": "Zhang San", "Address": "Beijing", "Age": 20},{"name": "John Doe", "Address": "Shanghai", "Age": 30},{"name": "Harry", "Address": "Shenzhen", "Age" : 35}]

At this point the server-side code is completed, the following client code writing; (ii) The client (person class, and the layout file that presents the data because it is simply omitted) ①: Gets the server-side JSON data and resolves the tool class Jsonparse.java necessary to import the package omitted

public class Jsonparse {

/**

* Parse JSON data

*

* @param URLPath

* @return Mlists

* @throws Exception

*/

public static list<person> Getlistperson (String urlpath) throws Exception {

list<person> mlists = new arraylist<person> ();

byte[] data = Readparse (URLPath);

Jsonarray array = new Jsonarray (new String (data));

for (int i = 0; i < array.length (); i++) {

Jsonobject item = array.getjsonobject (i);

String name = item.getstring ("name");

String address = item.getstring ("Address");

int age = Item.getint ("Age");

Mlists.add (new person (name, address, age));

}

return mlists;

}

/**

* Gets the byte array from the specified URL

*

* @param URLPath

* @return byte array

* @throws Exception

*/

public static byte[] Readparse (String urlpath) throws Exception {

Bytearrayoutputstream OutStream = new Bytearrayoutputstream ();

byte[] data = new byte[1024];

int len = 0;

URL url = new URL (urlpath);

HttpURLConnection conn = (httpurlconnection) url.openconnection ();

InputStream instream = Conn.getinputstream ();

while (len = instream.read (data))! =-1) {

Outstream.write (data, 0, Len);

}

Instream.close ();

return Outstream.tobytearray ();

}

}

②: Main Activity class

public class Mainactivity extends Activity {

Private Button Mbutton;

Private ListView Mlistview;

Use IP cannot use localhost or 127.0.0.1, because the Android emulator is bound to this IP by default, the LAN IP should be accessed here

private static final String URLPath = "Http://10.16.31.207/JsonWeb/JsonServlet";

private static final String TAG = "mainactivity";

private list<person> persons;

@Override

public void OnCreate (Bundle savedinstancestate) {

Super.oncreate (savedinstancestate);

Setcontentview (R.layout.main);

Mbutton = (Button) Findviewbyid (R.id.button1);

Mlistview = (ListView) Findviewbyid (R.ID.LISTVIEW1);

Mbutton.setonclicklistener (New Myonclicklistener ());

}

Private class Myonclicklistener implements Onclicklistener {

@Override

public void OnClick (View v) {

try {

Get the data after the JSON parsing succeeds

Persons = Jsonparse.getlistperson (URLPath);

list

for (int i = 0; i < persons.size (); i++) {

hashmap<string, object> map = new hashmap<string, object> ();

Map.put ("Name", Persons.get (i). GetName ());

Map.put ("Address", Persons.get (i). GetAddress ());

Map.put ("Age", Persons.get (i). Getage ());

Data.add (map);

}

Initialize the adapter, and bind the data

Simpleadapter _adapter = new Simpleadapter (Mainactivity.this,

Data, R.layout.listview_item, new string[] {"Name",

"Address", "age"}, new int[] {r.id.textview1,

R.id.textview2, r.id.textview3});

Mlistview.setadapter (_adapter);

} catch (Exception e) {

Toast.maketext (Mainactivity.this, "Parse Failed", "N"). Show ();

LOG.I (TAG, e.tostring ());

}

}

}

At this point the server side and the client code are introduced, running Android app results:

Android gets JSON parsing from server to display on client