Android Chat tool based on socket implementation _android

It's simple, there's no database, and there's no handling of exceptions.
Login: Enter user name click on login.
Send message: Specific format->touser:message
1. Server: Save online users

public class Online {
 private static online monline = null;
 Private linkedhashmap<string, socket> monlines = new linkedhashmap<string, socket> ();
  
 Private Online () {
 } public
  
 synchronized static online getinstance () {
  if (null = = Monline) {
   monline = new Online ();
  }
   
  return monline;
 }
  
 public void put (String key, socket socket) {
  if (!monlines.containskey (key)) {
   monlines.put (key, socket);
  }
 }
  
 Public Socket get (String key) {return
  monlines.get (key);
 }
  
 public void Remove (String key) {
  monlines.remove (key);
 }
}

2. Server: A simple socket server

Import Java.io.BufferedReader;
Import java.io.IOException;
Import Java.io.InputStreamReader;
Import Java.io.PrintWriter;
Import Java.net.ServerSocket;
 
Import Java.net.Socket; Login:uid//send:fromuser:touser:message//Logout:uid public class Server implements Runnable {private Socket Msock
 Et
 
 Private Online Monline;
  Public Server (socket socket) {msocket = socket;
 Monline = Online.getinstance (); @Override public void Run () {try {BufferedReader reader = new BufferedReader (new InputStreamReader) (MSOC
   Ket.getinputstream ()));
    
   String cmd = Reader.readline ();
    Login if (cmd.startswith ("login")) {String userName = Cmd.split (":") [1];
    Monline.put (UserName, Msocket);
     
    System.out.println (userName + "login ...");
    PrintWriter writer = new PrintWriter (Msocket.getoutputstream ());
    WRITER.PRINTLN ("Success");
   Writer.flush ();
    else if (Cmd.startswith ("send")) {System.out.println (cmd); string[] Cmds = Cmd.split (":");
    String from = cmds[1];
    Socket to = Monline.get (cmds[2]);
 
    String msg = cmds[3];
    PrintWriter writer = new PrintWriter (To.getoutputstream ());
     
    System.out.println ("Rec:" + from + ":" + cmds[2] + ":" + msg);
    Writer.println ("Rec:" + from + ":" + cmds[2] + ":" + msg);
   Writer.flush ();
     
    }else if (Cmd.startswith ("logout")) {System.out.println (cmd);
    String user = Cmd.split (":") [1];
    Monline.get (user). Close ();
     
    Monline.remove (user);
    PrintWriter writer = new PrintWriter (Msocket.getoutputstream ());
    WRITER.PRINTLN ("Success");
   Writer.flush ();
  } catch (Exception e) {e.printstacktrace ();
  } public static void Main (string[] args) throws Exception {ServerSocket server = new ServerSocket (8888);
  Boolean flag = true;
   while (flag) {New Thread (new Server (Server.accept ())). Start ();
  System.out.println ("User in ...");
 } server.close (); }
}

3. Client Login Interface

public class Mainactivity extends activity {
 private edittext muser;
  
 @Override
 protected void onCreate (Bundle savedinstancestate) {
  super.oncreate (savedinstancestate);
  Setcontentview (r.layout.activity_main);
   
  Muser = (edittext) Findviewbyid (r.id.username);
 }
  
 public void Login (view view) {
  final String userName = Muser.gettext (). toString (). Trim ();
  Login login = new Login (userName);
  Login.setonloginlistener (New Login.logincallback () {
   @Override public
   void Onlogin (Boolean success) {
    if (success) {
     Intent Intent = new Intent (mainactivity.this, chat.class);
     Intent.putextra ("User", userName);
     StartActivity (intent);
     Finish ();
    } else {
     Toast.maketext (mainactivity.this, Login failed, toast.length_short). Show ();}}
  ;
   
  Login.login ();
 }

4. Process Login

public class Login {private String musername;
  
 Private Logincallback Mcallback;
 Public Login (String userName) {musername = UserName;
 public void Setonloginlistener (Logincallback callback) {mcallback = callback;  Private Handler Mhandler = new Handler () {public void Handlemessage (msg) {switch (msg.what) {case
    Constant.SUCCESS:mCallback.onLogin (TRUE);
   Break
    Case Constant.FAILED:mCallback.onLogin (FALSE);
   Break
 }
  };
  
 };
    public void Login () {New Thread (new Runnable () {@Override public void run () {socket socket = NULL;
     try {socket = new socket ();
     Socket.connect (New Inetsocketaddress ("192.168.100.100", 8888), 4000);
     PrintWriter writer = new PrintWriter (Socket.getoutputstream ());
     WRITER.PRINTLN ("Login:" + musername);
      
     Writer.flush ();
     BufferedReader reader = new BufferedReader (New InputStreamReader (Socket.getinputstream ())); String line = Reader.readlINE ();
     System.out.println (line);
      if ("Success". Equals (line)) {pconnection.socket = socket;
     Mhandler.sendemptymessage (constant.success);
     }else {mhandler.sendemptymessage (constant.failed);
    }}catch (Exception e) {e.printstacktrace ();
 }}). Start ();
 Public interface Logincallback {public void Onlogin (Boolean success); }
}

5. Chat interface     

public class Chat extends activity {private String musername;
 Private EditText Medit;
  
 Private ListView mmessage;
 Private Receivermessage mrecmessage;
 Private SendMessage msendmesage;
 Private list<map<string, string>> mdata = new arraylist<map<string, string>> ();
  
 Private Messagesadapter Madapter;
  @Override protected void OnCreate (Bundle savedinstancestate) {super.oncreate (savedinstancestate);
   
  Setcontentview (r.layout.chat_layout);
  Musername = Getintent (). Getstringextra ("user");
  Medit = (edittext) Findviewbyid (R.id.edit);
   
  Mmessage = (ListView) Findviewbyid (r.id.message);
  Mrecmessage = new Receivermessage ();
  Mrecmessage.setonreceiverlistener (New Reclistener ());
   
  Mrecmessage.run ();
  Msendmesage = new SendMessage ();
   
  Msendmesage.setonsendlistener (New Sendlistener ());
  Madapter = new Messagesadapter (this, mdata);
 Mmessage.setadapter (Madapter); public void Send (view view) {string[] content = Medit.gettext (). toString (). Trim (). Split (":");
 Msendmesage.send (Musername, content[0], content[1]); Private class Reclistener implements Receivermessage.onreceiverlistener {@Override public void Onreceiver (Strin
   g user, String msg) {map<string, string> temp = new hashmap<string, string> ();
   Temp.put ("user", user);
   Temp.put ("msg", MSG);
   Temp.put ("pos", "right");
   Mdata.add (temp);
  Madapter.notifydatasetchanged ();  } Private class Sendlistener implements Sendmessage.onsendlistener {@Override public void OnSend (string[] msg)
   {map<string, String> temp = new hashmap<string, string> ();
   Temp.put ("User", "I");
   Temp.put ("MSG", msg[1]);
   Temp.put ("Pos", "left");
   Mdata.add (temp);
  Madapter.notifydatasetchanged (); @Override public boolean onoptionsitemselected (MenuItem item) {if r.id.logout = = Item.getitemid ()) {Logou
   T logout = new logout (); Logout.setonlogoutlistener (New Logout.onlogoutlistener () {@OverrIDE public void Onlogout (Boolean success) {if (success) {Toast.maketext (Chat.this, "Logoff succeeded", Toast.length_sh
      ORT). Show ();
     Finish ();
     }else {toast.maketext (Chat.this, logoff failed, Toast.length_short). Show ();
    
   }
    }
   });
  Logout.logout (Musername);
 return super.onoptionsitemselected (item);
  @Override public boolean Oncreateoptionsmenu (Menu menu) {getmenuinflater (). Inflate (R.menu.main, menu);
 return Super.oncreateoptionsmenu (menu); }
}

6. Send Message     

public class SendMessage {private Onsendlistener mlistener;
 public void Setonsendlistener (Onsendlistener listener) {Mlistener = listener;  Private Handler Mhandler = new Handler () {public void Handlemessage (msg) {Mlistener.onsend ((string[))
  Msg.obj);
 };
  
 }; Send:from:to:message public void Send (final string, final string, final string msg) {New Thread (new Runnab
    Le () {@Override public void run () {socket socket = NULL;
     try {socket = new socket ();
     Socket.connect (New Inetsocketaddress ("192.168.100.100", 8888), 4000);
     PrintWriter writer = new PrintWriter (Socket.getoutputstream ());
     Writer.println ("Send:" + from + ":" + to + ":" + msg);
      
     Writer.flush ();
      
     Message message = Mhandler.obtainmessage (constant.success, new string[] {to, msg});
    Message.sendtotarget ();
     catch (Exception e) {} finally {try {socket.close ();
    catch (IOException e) {  E.printstacktrace ();
 }}}). Start ();
 Public interface Onsendlistener {public void OnSend (string[] msg); }
}

7. Receiving messages, dead loops, but blocking, no problem     

public class Receivermessage {private Onreceiverlistener mlistener;
 public void Setonreceiverlistener (Onreceiverlistener listener) {Mlistener = listener; Private Handler Mhandler = new Handler () {public void Handlemessage (msg) {string[] Cmds = (string[))
   Msg.obj;
  Mlistener.onreceiver (Cmds[0], cmds[1]);
 };
  
 }; public void Run () {New Thread (new Runnable () {@Override public void run () {try {socket socket = Pconn
     Ection.socket;
      while (true) {System.out.println ("Wait for Message ...");
      BufferedReader reader = new BufferedReader (New InputStreamReader (Socket.getinputstream ()));
       
      String line = Reader.readline ();
       if (Line.startswith ("Rec")) {//rec:fromuser:touser:message string[] Cmds = Line.split (":");
       System.out.println (Cmds[0] + ":" + cmds[1] + ":" + cmds[2] + ":" + cmds[3]);
Message msg = Mhandler.obtainmessage (constant.success, new string[] {cmds[1], cmds[3]});       Msg.sendtotarget ();
    A catch (Exception e) {e.printstacktrace ());
 }}). Start ();
 Public interface Onreceiverlistener {public void Onreceiver (string user, string msg); }
}

8. Logout Login     

public class Logout {public Onlogoutlistener mlistener;
 public void Setonlogoutlistener (Onlogoutlistener listner) {mlistener = Listner; Private Handler Mhandler = new Handler () {public void Handlemessage (msg) {if (constant.success = Msg.
   What) {Mlistener.onlogout (true);
   }else {mlistener.onlogout (false);
 }
  };
  
 }; public void Logout (final String user) {new Thread (new Runnable () {@Override public void run () {try {S
     Ocket socket = new socket ();
     Socket.connect (New Inetsocketaddress ("192.168.100.100", 8888), 4000);
     PrintWriter writer = new PrintWriter (Socket.getoutputstream ());
     Writer.println ("Logout:" + user);
      
     Writer.flush ();
      
     BufferedReader reader = new BufferedReader (New InputStreamReader (Socket.getinputstream ()));
      if ("Success". Equals (Reader.readline ()) {pconnection.socket = null;
     Mhandler.sendemptymessage (constant.success); }else {Mhandler.Sendemptymessage (constant.failed);
    } catch (Exception e) {e.printstacktrace ();
 }}). Start ();
 Public interface Onlogoutlistener {public void Onlogout (Boolean success); }
}

9. Store the socket after login, use the socket when sending messages and receiving messages

public class Pconnection {public
 static socket socket;
}

I hope this article will help you to learn.