Java NIO樣本：多人網路聊天室

標籤：

一個多用戶端聊天室，支援多用戶端聊天，有如下功能：

• 功能1： 用戶端通過Java NIO串連到服務端，支援多用戶端的串連
• 功能2：用戶端初次串連時，服務端提示輸入暱稱，如果暱稱已經有人使用，提示重新輸入，如果暱稱唯一，則登入成功，之後發送訊息都需要按照規定格式帶著暱稱發送訊息
• 功能3：用戶端登入後，發送已經設定好的歡迎資訊和線上人數給用戶端，並且通知其他用戶端該用戶端上線
• 功能4：伺服器收到已登入用戶端輸入內容，轉寄至其他登入用戶端。
• 功能5 TODO：用戶端下線檢測  方案是：用戶端線上的時候發送心跳，服務端用TimeCacheMap自動刪除到期對象，同時通知線上使用者刪掉的使用者下線。

下面示範下效果，代碼見附錄！

 

啟動伺服器，監聽某個連接埠

伺服器console

Server is listening now...

 

啟動一個用戶端，串連伺服器

伺服器console

Server is listening now...Server is listening from client :/127.0.0.1:50206

用戶端console

Please input your name.

 

用戶端輸入一個暱稱

服務端console

Server is listening now...Server is listening from client :/127.0.0.1:50206Server is listening from client /127.0.0.1:50206 data rev is: byr1#@#

用戶端console

Please input your name.byr1welcome byr1 to chat room! Online numbers:1

 

再啟動另外一個用戶端，並輸入暱稱

服務端console

Server is listening now...Server is listening from client :/127.0.0.1:50206Server is listening from client /127.0.0.1:50206 data rev is: byr1#@#Server is listening from client :/127.0.0.1:50261Server is listening from client /127.0.0.1:50261 data rev is: byr2#@#

用戶端byr1 console

Please input your name.byr1welcome byr1 to chat room! Online numbers:1welcome byr2 to chat room! Online numbers:2

用戶端byr2 console

Please input your name.byr2welcome byr2 to chat room! Online numbers:2

 

用戶端byr1發送一個訊息，客戶byr2回一條訊息

服務端console

Server is listening now...Server is listening from client :/127.0.0.1:50206Server is listening from client /127.0.0.1:50206 data rev is: byr1#@#Server is listening from client :/127.0.0.1:50261Server is listening from client /127.0.0.1:50261 data rev is: byr2#@#Server is listening from client /127.0.0.1:50206 data rev is: byr1#@#hello byr2, a nice day, isn‘t it?Server is listening from client /127.0.0.1:50261 data rev is: byr2#@#fine

用戶端byr1 console

Please input your name.byr1welcome byr1 to chat room! Online numbers:1welcome byr2 to chat room! Online numbers:2hello byr2, a nice day, isn‘t it?byr2 say fine

用戶端byr2 console

Please input your name.byr2welcome byr2 to chat room! Online numbers:2byr1 say hello byr2, a nice day, isn‘t it?fine

 附錄：server和client代碼

server代碼

package com.huahuiyang.channel;import java.io.IOException;import java.net.InetSocketAddress;import java.nio.ByteBuffer;import java.nio.channels.Channel;import java.nio.channels.SelectionKey;import java.nio.channels.Selector;import java.nio.channels.ServerSocketChannel;import java.nio.channels.SocketChannel;import java.nio.charset.Charset;import java.util.HashSet;import java.util.Iterator;import java.util.Set;/** * 網路多用戶端聊天室 * 功能1： 用戶端通過Java NIO串連到服務端，支援多用戶端的串連 * 功能2：用戶端初次串連時，服務端提示輸入暱稱，如果暱稱已經有人使用，提示重新輸入，如果暱稱唯一，則登入成功，之後發送訊息都需要按照規定格式帶著暱稱發送訊息 * 功能3：用戶端登入後，發送已經設定好的歡迎資訊和線上人數給用戶端，並且通知其他用戶端該用戶端上線 * 功能4：伺服器收到已登入用戶端輸入內容，轉寄至其他登入用戶端。 *  * TODO 用戶端下線檢測 */public class ChatRoomServer {    private Selector selector = null;    static final int port = 9999;    private Charset charset = Charset.forName("UTF-8");    //用來記錄線上人數，以及暱稱    private static HashSet<String> users = new HashSet<String>();        private static String USER_EXIST = "system message: user exist, please change a name";    //相當於自訂協議格式，與用戶端協商好    private static String USER_CONTENT_SPILIT = "#@#";        private static boolean flag = false;        public void init() throws IOException    {        selector = Selector.open();        ServerSocketChannel server = ServerSocketChannel.open();        server.bind(new InetSocketAddress(port));        //非阻塞的方式        server.configureBlocking(false);        //註冊到選取器上，設定為監聽狀態        server.register(selector, SelectionKey.OP_ACCEPT);                System.out.println("Server is listening now...");                while(true) {            int readyChannels = selector.select();            if(readyChannels == 0) continue;             Set selectedKeys = selector.selectedKeys();  //可以通過這個方法，知道可用通道的集合            Iterator keyIterator = selectedKeys.iterator();            while(keyIterator.hasNext()) {                 SelectionKey sk = (SelectionKey) keyIterator.next();                 keyIterator.remove();                 dealWithSelectionKey(server,sk);            }        }    }        public void dealWithSelectionKey(ServerSocketChannel server,SelectionKey sk) throws IOException {        if(sk.isAcceptable())        {            SocketChannel sc = server.accept();            //非阻塞模式            sc.configureBlocking(false);            //註冊選取器，並設定為讀模數式，收到一個串連請求，然後起一個SocketChannel，並註冊到selector上，之後這個串連的資料，就由這個SocketChannel處理            sc.register(selector, SelectionKey.OP_READ);                        //將此對應的channel設定為準備接受其他用戶端請求            sk.interestOps(SelectionKey.OP_ACCEPT);            System.out.println("Server is listening from client :" + sc.getRemoteAddress());            sc.write(charset.encode("Please input your name."));        }        //處理來自用戶端的資料讀取請求        if(sk.isReadable())        {            //返回該SelectionKey對應的 Channel，其中有資料需要讀取            SocketChannel sc = (SocketChannel)sk.channel();             ByteBuffer buff = ByteBuffer.allocate(1024);            StringBuilder content = new StringBuilder();            try            {                while(sc.read(buff) > 0)                {                    buff.flip();                    content.append(charset.decode(buff));                                    }                System.out.println("Server is listening from client " + sc.getRemoteAddress() + " data rev is: " + content);                //將此對應的channel設定為準備下一次接受資料                sk.interestOps(SelectionKey.OP_READ);            }            catch (IOException io)            {                sk.cancel();                if(sk.channel() != null)                {                    sk.channel().close();                }            }            if(content.length() > 0)            {                String[] arrayContent = content.toString().split(USER_CONTENT_SPILIT);                //註冊使用者                if(arrayContent != null && arrayContent.length ==1) {                    String name = arrayContent[0];                    if(users.contains(name)) {                        sc.write(charset.encode(USER_EXIST));                                            } else {                        users.add(name);                        int num = OnlineNum(selector);                        String message = "welcome "+name+" to chat room! Online numbers:"+num;                        BroadCast(selector, null, message);                    }                }                 //註冊完了，發送訊息                else if(arrayContent != null && arrayContent.length >1){                    String name = arrayContent[0];                    String message = content.substring(name.length()+USER_CONTENT_SPILIT.length());                    message = name + " say " + message;                    if(users.contains(name)) {                        //不回傳給發送此內容的用戶端                        BroadCast(selector, sc, message);                    }                }            }                    }    }        //TODO 要是能檢測下線，就不用這麼統計了    public static int OnlineNum(Selector selector) {        int res = 0;        for(SelectionKey key : selector.keys())        {            Channel targetchannel = key.channel();                        if(targetchannel instanceof SocketChannel)            {                res++;            }        }        return res;    }        public void BroadCast(Selector selector, SocketChannel except, String content) throws IOException {        //廣播資料到所有的SocketChannel中        for(SelectionKey key : selector.keys())        {            Channel targetchannel = key.channel();            //如果except不為空白，不回傳給發送此內容的用戶端            if(targetchannel instanceof SocketChannel && targetchannel!=except)            {                SocketChannel dest = (SocketChannel)targetchannel;                dest.write(charset.encode(content));            }        }    }        public static void main(String[] args) throws IOException     {        new ChatRoomServer().init();    }}

 client代碼

package com.huahuiyang.channel;import java.io.IOException;import java.net.InetSocketAddress;import java.nio.ByteBuffer;import java.nio.channels.SelectionKey;import java.nio.channels.Selector;import java.nio.channels.SocketChannel;import java.nio.charset.Charset;import java.util.Iterator;import java.util.Scanner;import java.util.Set;public class ChatRoomClient {    private Selector selector = null;    static final int port = 9999;    private Charset charset = Charset.forName("UTF-8");    private SocketChannel sc = null;    private String name = "";    private static String USER_EXIST = "system message: user exist, please change a name";    private static String USER_CONTENT_SPILIT = "#@#";        public void init() throws IOException    {        selector = Selector.open();        //串連遠程主機的IP和連接埠        sc = SocketChannel.open(new InetSocketAddress("127.0.0.1",port));        sc.configureBlocking(false);        sc.register(selector, SelectionKey.OP_READ);        //開闢一個新線程來讀取從伺服器端的資料        new Thread(new ClientThread()).start();        //在主線程中 從鍵盤讀取資料輸入到伺服器端        Scanner scan = new Scanner(System.in);        while(scan.hasNextLine())        {            String line = scan.nextLine();            if("".equals(line)) continue; //不允許發空訊息            if("".equals(name)) {                name = line;                line = name+USER_CONTENT_SPILIT;            } else {                line = name+USER_CONTENT_SPILIT+line;            }            sc.write(charset.encode(line));//sc既能寫也能讀，這邊是寫        }            }    private class ClientThread implements Runnable    {        public void run()        {            try            {                while(true) {                    int readyChannels = selector.select();                    if(readyChannels == 0) continue;                     Set selectedKeys = selector.selectedKeys();  //可以通過這個方法，知道可用通道的集合                    Iterator keyIterator = selectedKeys.iterator();                    while(keyIterator.hasNext()) {                         SelectionKey sk = (SelectionKey) keyIterator.next();                         keyIterator.remove();                         dealWithSelectionKey(sk);                    }                }            }            catch (IOException io)            {}        }        private void dealWithSelectionKey(SelectionKey sk) throws IOException {            if(sk.isReadable())            {                //使用 NIO 讀取 Channel中的資料，這個和全域變數sc是一樣的，因為只註冊了一個SocketChannel                //sc既能寫也能讀，這邊是讀                SocketChannel sc = (SocketChannel)sk.channel();                                ByteBuffer buff = ByteBuffer.allocate(1024);                String content = "";                while(sc.read(buff) > 0)                {                    buff.flip();                    content += charset.decode(buff);                }                //若系統發送通知名字已經存在，則需要換個暱稱                if(USER_EXIST.equals(content)) {                    name = "";                }                System.out.println(content);                sk.interestOps(SelectionKey.OP_READ);            }        }    }                public static void main(String[] args) throws IOException    {        new ChatRoomClient().init();    }}

 

Java NIO樣本：多人網路聊天室