java socket client-server-client小例子

妖狐艹你老母 2022-08-20 14:07 269阅读 0赞

首先定义一个Msg类 类中包含 发送者 接收者 及消息

public class Msg {
        private String sender;
        private String receiver;
        private String msg;
    
        public String getSender() {
            return sender;
        }
    
        public void setSender(String sender) {
            this.sender = sender;
        }
    
        public String getReceiver() {
            return receiver;
        }
    
        public void setReceiver(String receiver) {
            this.receiver = receiver;
        }
    
        public String getMsg() {
            return msg;
        }
    
        public void setMsg(String msg) {
            this.msg = msg;
        }
    }

然后定义一个 全局Map 来存储在线人数

public class OnlineMap {
        private final static Map<String, Object> onlineMap = Maps.newHashMap();
        public static Object get(String key) {
            return onlineMap.get(key);
        }
        public static void put(String key, Object obj) {
            onlineMap.put(key, obj);
        }
        public static int getCount() {
            return onlineMap.size();
        }
        public static void remove(String key) {
            onlineMap.remove(key);
        }
        public static String getOnlineInfo() {
            Iterator iterator = onlineMap.keySet().iterator();
            StringBuilder builder = new StringBuilder();
            while (iterator.hasNext()) {
                builder.append(iterator.next()).append(",");
            }
            return builder.toString();
        }
    }

接着定义 服务端

public class TalkServer {
        //用户集合
        private static ArrayList<Socket> list = new ArrayList<Socket>();
    
        public static void main(String[] args) {
    
            //上线用户
            Socket s = null;
    
            //用户
            String ip = null;
            String name = null;
            try {
    
                //构建服务器对象
                ServerSocket ss = new ServerSocket(1234);
    
                //构建 用户集合
                list = new ArrayList<Socket>();
    
                System.out.println("服务器准备就绪 ...");
    
                //循环监听
                while(true){
    
                    //上线用户
                    s = ss.accept();
    
                    BufferedReader reader = new BufferedReader(new InputStreamReader(s.getInputStream()));
                    //上线的人都添加到 集合中
                    list.add(s);
                    name = reader.readLine();
                    OnlineMap.put(name, s);
                    System.out.println(OnlineMap.getOnlineInfo());
                    //获取 Socket IP
                    ip = s.getInetAddress().getHostAddress();
                    System.err.println( ip + name +" 用户上线了 , 当前在线用户为: " + list.size() + "人 !"+OnlineMap.getOnlineInfo() );
    
                    //构建 发送信息线程
                    M2MSend send = new M2MSend(s, name);
                    send.start();
    
                }
    
            } catch (IOException e) {
               e.printStackTrace();
            }
    
        }
    
        public static ArrayList<Socket> getList() {
            return list;
        }
    
        public static void setList(ArrayList<Socket> list) {
            TalkServer.list = list;
        }
    
    }

服务端中包含一个 转发消息的 线程类M2MSend

public class M2MSend extends Thread{
        //用户集合
        private ArrayList<Socket> list = TalkServer.getList();
        //当前用户
        private Socket s;
        private String name;
        public M2MSend(Socket s, String name){
            this.s = s;
            this.name = name;
        }
    
        public void run(){
    
            //获取该用户 IP
            String ip = s.getInetAddress().getHostAddress();
    
            try {
    
                //读取用户信息
                BufferedReader reader = new BufferedReader(new InputStreamReader(s.getInputStream()));
                ObjectMapper mapper = JsonUtil.getMapper();
                //不断的读取写出数据
                while(true){
    
                    //接收数据
                    String info = null;
    
                    //如果读取信息不为空
                    if((info=reader.readLine()) != null){
                        Msg msg = mapper.readValue(info, Msg.class);
                        Socket ss = (Socket) OnlineMap.get(msg.getReceiver());
                        //遍历所有的在线用户,并且把信息发送过去
                        if (ss != null) {
                            PrintWriter pw = new PrintWriter(ss.getOutputStream());
    //                        msg.setMsg(ip + " "+ msg.getSender() +" 说: " + msg.getMsg());
                            //写入信息
                            pw.println(mapper.writeValueAsString(msg));
                            pw.flush();
                        } else {
                            for(Socket sss : list){
    
                                //获取对象的输出流
                                PrintWriter pw;
                                pw = new PrintWriter(sss.getOutputStream());
    //                            msg.setMsg(ip + " "+ msg.getSender() +" 说: " + msg.getMsg());
                                //写入信息
                                pw.println(mapper.writeValueAsString(msg));
                                pw.flush();
    
                            }
                        }
    
                    }
                }
    
            } catch (IOException e1) {
                //用户下线
                list.remove(s);
                OnlineMap.remove(name);
                System.err.println(ip + name +" 已下线 , 当前在线人数为: " + list.size() + " 人 !"+OnlineMap.getOnlineInfo());
            }
    
    
        }
    }

然后定义客户端

public class TalkClient {
    
        public static void main(String[] args) {
    
            try {
    
                //先从键盘接收信息
                BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    
                System.out.println("请输入昵称：");
                String sender = br.readLine();
                //构建客户端对象
                Socket s = new Socket("localhost", 1234);
                //写入到 Socket 中
                PrintWriter pw = new PrintWriter(s.getOutputStream());
                pw.println(sender);
                pw.flush();
                ObjectMapper mapper = JsonUtil.getMapper();
                //启动线程
                M2MReceive receive = new M2MReceive(s);
                receive.start();
                while (true) {
                    Msg msg = new Msg();
                    System.out.println("请输入接收人：");
                    String receiver = br.readLine();
                    System.out.println("请输入发送的消息：");
                    String message = br.readLine();
                    msg.setSender(sender);
                    msg.setReceiver(receiver);
                    msg.setMsg(message);
    
                    if (msg != null) {
                        System.out.println("自己说：" + message);
                        //写出
                        pw.println(mapper.writeValueAsString(msg));
                        pw.flush();
                    }
    
                }
    
    
            } catch (UnknownHostException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
    
        }
    }

客户端中包含一个 接收服务端消息的线程类M2MReceive

public class M2MReceive extends Thread{
        private Socket s;
    
        public M2MReceive(Socket s){
            this.s = s;
        }
    
        public void run(){
    
            try {
                String ip = s.getInetAddress().getHostAddress();
                //构建输入流
                BufferedReader br = new BufferedReader(new InputStreamReader(s.getInputStream()));
                ObjectMapper mapper = JsonUtil.getMapper();
                //不断的接收信息
                while(true){
    
                    String info = null;
    
                    //接收信息
                    if((info=br.readLine()) != null){
                        System.out.println(info);
                        Msg msg = mapper.readValue(info, Msg.class);
                        System.out.println(ip + " "+ msg.getSender() +" 说: " + msg.getMsg());
                        System.out.println("请输入接收人：");
                    }
    
                }
    
    
            } catch (IOException e) {
                e.printStackTrace();
            }
    
        }
    }

运行说明

首先 运行server main方法 客户端登陆后会显示登陆人数 及 登陆人昵称列表

其次运行 client main方法 然后 客户端 会让在控制台输入昵称 该昵称为客户端的标识 然后会询问你 要发送给哪个昵称  然后输入消息

就可以 在对应昵称的客户端中看到发送的消息了

该例子用到了 apache的 jackson  和 guava的 Maps  需下载引入