Android-Sends data (GET) to the server.

Here, using the HTTP protocol, the request is sent to the server through a GET request, which is suitable for small amounts of data and low data security requirements.

One, server side, using servlet.

On the server side, define a subclass of HttpServlet, and a subclass of filter (for uniform encoding to prevent garbled characters).

Package Spt.servlet;import Java.io.ioexception;import Javax.servlet.servletexception;import Javax.servlet.annotation.webservlet;import Javax.servlet.http.httpservlet;import Javax.servlet.http.httpservletrequest;import javax.servlet.http.httpservletresponse;/** * type ' http://localhost : 8080/receiveandroid/servletforgetmethod?name=juk&pwd=lis ' * for the browser. */@WebServlet ("/servletforgetmethod") public class Servletforgetmethod extends HttpServlet {private static final long Serialversionuid = 1l;/** * @see httpservlet#httpservlet () */public Servletforgetmethod () {super ();} /** * @see Httpservlet#doget (httpservletrequest request, HttpServletResponse * response) */protected void Doget (HttpS Ervletrequest request, HttpServletResponse response) throws Servletexception, IOException {String name = Request.getparameter ("name"); String pwd = request.getparameter ("pwd"); System.out.println ("Name:" + name + "pwd:" + pwd);} /** * @see Httpservlet#dopost (httpservletrequest request, HttpserVletresponse * response) */protected void DoPost (HttpServletRequest request, httpservletresponse response) throws Ser Vletexception, IOException {//TODO auto-generated method stub}}

 

Package Spt.servlet.filter;import Java.io.ioexception;import Java.io.unsupportedencodingexception;import Javax.servlet.filter;import Javax.servlet.filterchain;import Javax.servlet.filterconfig;import Javax.servlet.servletexception;import Javax.servlet.servletrequest;import Javax.servlet.servletresponse;import Javax.servlet.annotation.webfilter;import Javax.servlet.http.httpservletrequest;import  Javax.servlet.http.httpservletrequestwrapper;//filter all servlets. @WebFilter ("/*") public class Encodingfilter Implements Filter {public void DoFilter (ServletRequest servletrequest, Servletresponse servletresponse, Filterchain Filterchain) throws IOException, servletexception {httpservletrequest httpreq = (httpservletrequest) servletRequest;if ("GET". Equals (Httpreq.getmethod ())) Filterchain.dofilter (new Httpservletrequestencodingwrapper (Httpreq), Servletresponse), else {httpreq.setcharacterencoding ("Utf-8"); Filterchain.dofilter (Httpreq, Servletresponse);}} public void init (Filterconfig filterconfig) throws Servletexception {//TODO auto-generated method Stub}/**inner class dealing for ' GET ' method. * @author Administrator *2015-1-27 */private class Httpservletrequestencodingwrapper extends Httpservletrequestwrapper {Public Httpservletrequestencodingwrapper (HttpServletRequest request) {super (request);} @Overridepublic string GetParameter (string name) {//encode with ' ISO ', and than decode with ' UTF '. String val = Super.getrequest (). GetParameter (name), if (null! = val) {try {return new String (Val.getbytes ("iso8859-1"), "U Tf-8 ");} catch (Unsupportedencodingexception e) {e.printstacktrace ();}} return Super.getparameter (name);}} public void Destroy () {//TODO auto-generated method stub}}

On the host (server), enter ' Http://localhost:8080/ReceiveAndroid/ServletForGETMethod?name=juk&pwd=lis ' in the browser, if you want to print the desired results in the console, Indicates that the server-side servlet has been written.

Second, the Android business logic Layer class, mainly is the business logic independent of the activity of Android.

Package Spt.http.get.assist;import Java.io.ioexception;import Java.net.httpurlconnection;import Java.net.malformedurlexception;import Java.net.url;import Java.net.urlencoder;import Java.util.HashMap;import Java.util.map;import Java.util.map.entry;import android.os.handler;/** The class that the user sends data to the server side. * @author Administrator * */public class Senddatatoserver {private static final int time_out = 10000;//timeout.//URL of the connection server . private static final String URL = "Http://192.168.1.101:8080/ReceiveAndroid/ServletForGETMethod";// Identifies whether the connection to the server was successful. public static final int send_success = 1;public static final int send_fail = 0;private Handler Handler = null ;p ublic senddatatoserver (Handler Handler) {this.handler = Handler;} /** * Send data to the server. * * @param name * @param pwd */public void Send (string name, string pwd) {//Here the params is to be passed to another method, plus final in order to prevent modification. Final MAP&L T String, string> params = new hashmap<string, string> ();p arams.put ("name", name);p arams.put ("pwd", pwd);// Start a new thread to connect to the server. New Runnable () {@Overridepublic void Run () {//Use GET request to connect. try {if (Getsend (params, URL, "Utf-8")) Handler.sendemptymessage (send_success); Elsehandler.sendemptymessage (Send_fail);} catch (Malformedurlexception e) {e.printstacktrace ();} catch (IOException e) {e.printstacktrace ();}}). Start ();} /** the method that sent the GET request. * @param the key-value pair of the params request parameter. * @param URL * @param encoding encodes the parameter values using the specified encoding. * @return * @throws malformedurlexception * @throws ioexception */private boolean getsend (map<string, string> params , String url,string encoding) throws Malformedurlexception, IOException {StringBuilder sb = new StringBuilder ();//Add to URL Parameters. Sb.append (URL). Append ("?"); For (entry<string, string> param:params.entrySet ()) {Sb.append (Param.getkey ()). Append ("="). Append ( Urlencoder.encode (Param.getvalue (), encoding)). Append ("&");} if (params.size () > 0) Sb.deletecharat (sb.length ()-1); Remove the ' & ' at the end. HttpURLConnection conn = (httpurlconnection) New URL (Sb.tostring ()). OpenConnection (); Conn.setconnecttimeout (TIME_ OUT); conn. Setrequestmethod ("GET"); Get is case sensitive. return Conn.getresponsecode () = = 200; equals 200 to send success.}}

  III: Activity class:

Package Spt.http.get.activity;import Java.lang.ref.weakreference;import Spt.http.get.assist.SendDataToServer; Import Android.app.activity;import android.os.bundle;import Android.os.handler;import Android.os.Message;import Android.view.view;import Android.widget.button;import Android.widget.edittext;import Android.widget.Toast;public Class Mainactivity extends Activity {//view.private EditText edt_name = null;private EditText edt_pwd = null;private Butto n BTN_OK = null, @Overrideprotected void OnCreate (Bundle savedinstancestate) {super.oncreate (savedinstancestate); Setcontentview (R.layout.activity_main); Initview (); Initlistener ();} /** * Initialize view. */private void Initview () {edt_name = (EditText) Findviewbyid (r.id.edt_name); edt_pwd = (EditText) Findviewbyid (R.id.edt _PWD) Btn_ok = (Button) Findviewbyid (R.ID.BTN_OK);//test:edt_name.settext ("Hello"); Edt_pwd.settext ("abc");} /** uses static internal classes to resolve the ' This Handler class should is static or leaks might occur ' to avoid memory leaks. * @author Administrator * */private Static classStatushandler extends Handler {weakreference<mainactivity> imainactivity = Null;public Statushandler ( Mainactivity mainactivity) {imainactivity = new weakreference<mainactivity> (mainactivity);} @Overridepublic void Handlemessage (Message msg) {switch (msg.what) {case senddatatoserver.send_success:// There are Imainactivity.get () and Imainactivity.getclass (). Toast.maketext (Imainactivity.get (), "Send Success", Toast.length_short). Show (); Break;case Senddatatoserver.send_fail: Toast.maketext (Imainactivity.get (), "Send Failed", Toast.length_short). Show (); Break;default:throw New RuntimeException (" Unknown send result! ");}} /** * Handler that handles the status of whether the send is successful. */private final Handler Handler = new Statushandler (this);/** * Initialize listener. */private void Initlistener () {Btn_ok.setonclicklistener (new Button.onclicklistener () {@Overridepublic void OnClick ( View v) {String name = Edt_name.gettext (). toString (); String pwd = Edt_pwd.gettext (). toString (); if (Name.isempty () | | | Pwd.isempty ()) {Toast.maketext (Mainactivity.this, " User name and password cannot be empty ", toast.length_short). Show (); return;} New Senddatatoserver (handler). Send (name, PWD);}});}}

A little note is that the subclass of Handler in the activity class is defined as a static class and holds a weak reference to the activity to prevent memory leaks. Brief explanation in my blog Android-this Handler class should be static or Leaks might occur. In.

Four, add the necessary permissions

In Androidmanifest.xml, add

<android:name= "Android.permission.INTERNET"/>

Access to the network.

Android-Sends data (GET) to the server.