HTTP request-android

I. Introduction of HttpClient

HttpClient is used to simulate HTTP requests, in essence, the HTTP request is simulated and sent to the Web server;

Android has integrated the httpclient, so it can be used directly;

Note: Here HttpClient code can not only apply to Android, but also to the General Java program;

HTTP GET Core code:

(1) Defaulthttpclient client = new Defaulthttpclient ();

(2) httpget get = new HttpGet (String URL);//The URL here is http://..../path?arg1=value&....argn=value

(3) HttpResponse response = Client.execute (get); Impersonation Request

(4) Int code = Response.getstatusline(). Getstatuscode ();// Return Response code

(5) inputstream in = Response.getEntity(). getcontent ();// data returned by the server

HTTP POST Core code:

(1) Defaulthttpclient client = new Defaulthttpclient ();

(2) Basicnamevaluepair pair = new Basicnamevaluepair (String name,string value);//Create a field for the request header , Like Content-type,text/plain.

(3) urlencodedformentity entity = new Urlencodedformentity (list<namevaluepair> list,string encoding);// URL encoding of a custom request header

(4) HttpPost post = new HttpPost (String URL);//The URL here is Http://..../path

(5) post.setentity (entity);

(6) HttpResponse response = Client.execute (POST);

(7) Int code = Response.getstatusline (). Getstatuscode (); Return Response Code

(8) InputStream in = Response.getentity (). getcontent ();//data returned by the server

Join in Androidmanifest.xml:

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

Second, server-side code

The server-side code and the code that makes the request through URLConnection are the same:

 PackageOrg.xiazdong.servlet; Importjava.io.IOException; ImportJava.io.OutputStream; Importjavax.servlet.ServletException; ImportJavax.servlet.annotation.WebServlet; ImportJavax.servlet.http.HttpServlet; Importjavax.servlet.http.HttpServletRequest; ImportJavax.servlet.http.HttpServletResponse; @WebServlet ("/servlet1")   Public classServlet1extendsHttpServlet {protected voidDoget (HttpServletRequest request, httpservletresponse response)throwsservletexception, IOException {String nameparameter= Request.getparameter ("name"); String Ageparameter= Request.getparameter ("Age"); String name=NewString (Nameparameter.getbytes ("iso-8859-1"), "UTF-8"); String Age=NewString (Ageparameter.getbytes ("iso-8859-1"), "UTF-8"); System.out.println ("GET"); System.out.println ("Name=" +name); System.out.println ("Age=" +Age ); Response.setcharacterencoding ("UTF-8"); OutputStream out= Response.getoutputstream ();//Return DataOut.write ("GET request succeeded!". GetBytes ("UTF-8"));      Out.close (); }        protected voidDoPost (HttpServletRequest request, httpservletresponse response)throwsServletexception, IOException {request.setcharacterencoding ("UTF-8"); String name= Request.getparameter ("name"); String Age= Request.getparameter ("Age"); System.out.println ("POST"); System.out.println ("Name=" +name); System.out.println ("Age=" +Age ); Response.setcharacterencoding ("UTF-8"); OutputStream out=Response.getoutputstream (); Out.write ("POST request succeeded!". GetBytes ("UTF-8"));                Out.close (); }    } 

Third, the Android client code

The effect is as follows:

Join in Androidmanifest.xml:

[HTML] < uses-permission android:name= "Android.permission.INTERNET"/>

Mainactivity.java

[java]  Package org.xiazdong.network.httpclient;    Import java.io.bytearrayoutputstream;  Import java.io.ioexception;  Import java.io.inputstream;  import java.net.urlencoder;  Import java.util.arraylist;  Import java.util.list;    Import org.apache.http.httpresponse;  Import org.apache.http.namevaluepair;  Import org.apache.http.client.entity.urlencodedformentity;  Import org.apache.http.client.methods.httpget;  Import org.apache.http.client.methods.httppost;  Import org.apache.http.impl.client.defaulthttpclient;  Import org.apache.http.message.basicnamevaluepair;    Import android.app.activity;  Import android.os.bundle;  import android.view.view;  Import android.view.view.onclicklistener;  Import android.widget.button;  Import android.widget.edittext;  Import android.widget.toast;   

public class Mainactivity extends Activity {

Private EditText name, age;

Private Button Getbutton, Postbutton;

Private Onclicklistener listener = new Onclicklistener () {

@Override

public void OnClick (View v) {

try{

if (postbutton==v) {

/*                       * Namevaluepair represents a header,list<namevaluepair> store all header fields                       * Urlencodedformentity URL encoding similar to urlencoder statement                       * HttpPost POST request similar to HTTP                       * Client.execute () Similar to making a request and returning response                       */                      

Defaulthttpclient client = new Defaulthttpclient ();

list<namevaluepair> list = new arraylist<namevaluepair> ();

Namevaluepair Pair1 = new Basicnamevaluepair ("name", Name.gettext (). toString ());

Namevaluepair Pair2 = new Basicnamevaluepair ("Age", Age.gettext (). toString ());

List.add (PAIR1);

List.add (PAIR2);

urlencodedformentity entity = new Urlencodedformentity (list, "UTF-8");

HttpPost post = new HttpPost ("Http://192.168.0.103:8080/Server/Servlet1");

Post.setentity (entity);

HttpResponse response = Client.execute (POST);

if (Response.getstatusline (). Getstatuscode () ==200) {

InputStream in = Response.getentity (). getcontent ();//Receive server data and display on toast

String str = readString (in);

Toast.maketext (Mainactivity.this, str, toast.length_short). Show ();

}

else Toast.maketext (Mainactivity.this, "Post submission failed", Toast.length_short). Show ();

}

if (getbutton==v) {

Defaulthttpclient client = new Defaulthttpclient ();

StringBuilder buf = new StringBuilder ("Http://192.168.0.103:8080/Server/Servlet1");

Buf.append ("?");

Buf.append ("Name=" +urlencoder.encode (Name.gettext (). toString (), "UTF-8") + "&");

Buf.append ("age=" +urlencoder.encode (Age.gettext (). toString (), "UTF-8"));

HttpGet get = new HttpGet (buf.tostring ());

HttpResponse response = Client.execute (get);

if (Response.getstatusline (). Getstatuscode () ==200) {

InputStream in = Response.getentity (). getcontent ();

String str = readString (in);

Toast.maketext (Mainactivity.this, str, toast.length_short). Show ();

}

else Toast.maketext (mainactivity.this, "Get Commit Failed", Toast.length_short). Show ();

}

}

catch (Exception e) {}

}

};

@Override

public void OnCreate (Bundle savedinstancestate) {          super.oncreate ( savedinstancestate);          setcontentview (r.layout.main);           name = (EditText) This.findviewbyid (r.id.name);           age = (EditText) This.findviewbyid (r.id.age);          Getbutton = (Button) This.findviewbyid (R.id.getbutton);          Postbutton = (Button) This.findviewbyid (R.id.postbutton);          Getbutton.setonclicklistener (listener);          Postbutton.setonclicklistener (listener);     }      protected String ReadString (InputStream in) throws Exception {          byte[]data = new byte[ 1024];  &NBsp;       int length = 0;          Bytearrayoutputstream bout = new Bytearrayoutputstream ();          while (( Length=in.read (data)!=-1) {              bout.write ( data,0,length);         }           return new String (Bout.tobytearray (), "UTF-8");               } } 

HTTP request-android