Android UDP communication

Function:

Achieve a single pitch:

Importjava.net.*;ImportJava.io.*; Public classudprecv{/** Create the receive side of the UDP transmission * 1. To establish a UDP socket service because it is to receive data, you must specify the port number * 2, create a packet, to store the received data. Easily process data with packet objects * 3, use the Receive method of the socket service to store the received data in a packet * 4, resolve data in a packet by means of a packet * 5, close the resource * throw a big exception: IOException 
    */     Public Static voidMain (string[] args)throwsioexception{//1, create the UDP socket serviceDatagramsocket ds =NewDatagramsocket (10000); //2. Create a packet        byte[] buf =New byte[1024]; Datagrampacket DP=NewDatagrampacket (buf,buf.length); //3, use the Received method to store the packet in a packetDs.receive (DP);//Block Type//4. Parse the data in the packet object by means of the methodString IP =dp.getaddress (). gethostaddress (); intPort =Dp.getport (); String content=NewString (Dp.getdata (), 0, Dp.getlength ()); SYSTEM.OUT.PRINTLN (IP+ "::" +port+ ":" +content); /*send back phone data*/        //first get the port and addressInetAddress addr =dp.getaddress (); String Sendstr= "Hello!" I am the server "; byte[] sendbuf; SendBuf= Sendstr.getbytes ("Utf-8");//must convert UTF8, otherwise android display garbledDatagrampacket Sendpacket=NewDatagrampacket (SendBuf, sendbuf.length, addr, port);        Ds.send (Sendpacket); //5 Closing ResourcesDs.close (); }}

Udprecv.java

Android Client Backend code:

 Packagecom.simpleclientudp;ImportJava.io.BufferedReader;ImportJava.io.BufferedWriter;Importjava.io.IOException;ImportJava.io.InputStreamReader;ImportJava.io.OutputStreamWriter;ImportJava.net.DatagramPacket;ImportJava.net.DatagramSocket;Importjava.net.InetAddress;ImportJava.net.Socket;Importandroid.app.Activity;ImportAndroid.os.Bundle;ImportAndroid.view.Menu;ImportAndroid.view.MenuItem;ImportAndroid.widget.EditText; Public classMainactivityextendsActivity {EditText show; @Overrideprotected voidonCreate (Bundle savedinstancestate) {Super. OnCreate (savedinstancestate);        Setcontentview (R.layout.activity_main); Show=(EditText) Findviewbyid (r.id.show); NewThread () {@Override Public voidrun () {Try            {                //1.udpsocket service object, created using Datagramsocket, can indicate local IP and port//of course it can be done without specifying that it has been tested successfully//now just indicate that the phone port is 8888Datagramsocket ds =NewDatagramsocket (8888); //2. Encapsulate the data you want to send into a packetString str = "UDP tranmsimit,i am Mobilephone"; byte[] buf =str.getbytes ("Utf-8"); Datagrampacket DP=NewDatagrampacket (Buf,buf.length,inetaddress.getbyname ("192.168.1.108"), 10000); //3.udp Send, use socket service to send data packetsDs.send (DP); /*Receive Data*/                byte[] Recvbuf =New byte[100]; Datagrampacket Recvpacket=NewDatagrampacket (Recvbuf, recvbuf.length);                Ds.receive (Recvpacket); String Recvstr=NewString (Recvpacket.getdata (), 0, Recvpacket.getlength ()); Show.settext ("Received: \ T" +recvstr); //4. Close the connectionDs.close (); }            Catch(IOException e) {e.printstacktrace ();    }}}.start (); }}

Front Code:

<?xml version= "1.0" encoding= "Utf-8"? ><linearlayout xmlns:android= "Http://schemas.android.com/apk/res/android"android:orientation= "Vertical"Android:layout_width= "Fill_parent"Android:layout_height= "Fill_parent" > <EditText Android:id= "@+id/show"Android:layout_width= "Fill_parent"Android:layout_height= "Wrap_content"android:cursorvisible= "false"android:editable= "false"Android:ems= "Ten" > <requestfocus/> </EditText> <Button Android:id= "@+id/button1"Android:layout_width= "Wrap_content"Android:layout_height= "Wrap_content"Android:text= "UDP Client"/></linearlayout>

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Permission code:

<?xml version= "1.0" encoding= "Utf-8"? ><manifest xmlns:android= "Http://schemas.android.com/apk/res/android" Package= "COM.SIMPLECLIENTUDP"Android:versioncode= "1"Android:versionname= "1.0" > <uses-SDK Android:minsdkversion= "14"android:targetsdkversion= "/>" <uses-permission android:name= "Android.permission.INTERNET"/> <Application Android:allowbackup= "true"Android:icon= "@drawable/ic_launcher"Android:label= "@string/app_name"Android:theme= "@style/apptheme" > <Activity Android:name=". Mainactivity "Android:label= "@string/app_name" > <intent-filter> <action android:name= "Android.intent.action.MA In "/> <category android:name=" Android.intent.category.LAUNCHER "/> </intent-filter&        Gt </activity> </application></manifest>

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Effect:

Android UDP communication