Java实现聊天室（单线程及多线程版）

港控/mmm° 2021-11-02 11:02 517阅读 0赞

Socket编程  
两个核心类：

ServerSocket——基站类
    public ServerSocket(int port)//在本机根据指定端口号创建服务器
    public Socket accept()//侦听并接收连接到本服务器的客户端连接，
    //此方法会一直阻塞，直到有一个客户端成功连接，返回此连接。
    
    Socket——客户端类
    public Socket(String host,int port)//根据指定ip和端口号创建套接字并连接到远程服务器端。
    public InputStream getInputStream()//返回此套接字的输入流
    public OutputStream getOutputStream()//返回此套接字的输出流

**单线程聊天室**

服务器类：

import java.io.PrintStream;
    import java.net.ServerSocket;
    import java.net.Socket;
    import java.util.Scanner;
    
    public class singleThreadServer { 
        public static void main(String[] args) throws Exception { 
            //1.建立基站
            ServerSocket server = new ServerSocket(6666);
            //2.等待客户端连接
            System.out.println("等待客户端连接");
            Socket socket = server.accept();
            //3.建立连接后，进行数据的输入输出
            PrintStream printStream = new PrintStream(socket.getOutputStream(),true,"UTF-8");
            printStream.println("hello,i am server!");
            Scanner scanner = new Scanner(socket.getInputStream());
            if (scanner.hasNext()){ 
                System.out.println("客户端发来的信息为："+scanner.nextLine());
            }
            //关闭流
            printStream.close();
            scanner.close();
            socket.close();
        }
    }

客户端类：

import java.io.PrintStream;
    import java.net.Socket;
    import java.util.Scanner;
    
    public class singleThreadClient { 
        public static void main(String[] args) throws Exception { 
            //1.建立连接
            Socket socket = new Socket("127.0.0.1",6666);
            //2.进行数据的输入输出
            Scanner scanner = new Scanner(socket.getInputStream());
            if (scanner.hasNext()){ 
                System.out.println("从服务器发来的信息为："+scanner.nextLine());
            }
            PrintStream printStream = new PrintStream(socket.getOutputStream(),true,"UTF-8");
            printStream.print("hello,i am client!");
            //3.关闭流
            printStream.close();
            scanner.close();
            socket.close();
        }
    }

**多线程聊天室**

客户端：

import java.io.IOException;
    import java.io.PrintStream;
    import java.net.Socket;
    import java.util.Scanner;
    //读线程
    class ReadFromServer implements Runnable{ 
        private Socket client;
        public ReadFromServer(Socket client) { 
            this.client = client;
        }
        @Override
        public void run() { 
            try { 
                //获取输入流来取得服务器发来的信息
                Scanner in = new Scanner(client.getInputStream());
                while (true){ 
                    if (client.isClosed()){ 
                        System.out.println("客户端已经关闭");
                        in.close();
                        break;
                    }
                    if(in.hasNext()){ 
                        String msgFromServer = in.nextLine();
                        System.out.println("服务器发来的信息为："+msgFromServer);
                    }
                }
            } catch (IOException e) { 
                e.printStackTrace();
            }
        }
    }
    
    //写线程
    class SendMsgToServer implements Runnable{ 
        private Socket client;
        public SendMsgToServer(Socket client) { 
            this.client = client;
        }
        @Override
        public void run() { 
            try { 
                PrintStream out = new PrintStream(client.getOutputStream(),true,"UTF-8");
                Scanner in = new Scanner(System.in);
                while (true){ 
                    System.out.println("请输入要向服务器发送的信息..");
                    String strFromUser = "";
                    if (in.hasNext()){ 
                        strFromUser = in.nextLine();
                    }
                    //向服务器发送信息
                    out.println(strFromUser);
                    //byebye
                    if (strFromUser.contains("byebye")){ 
                        System.out.println("当前客户端退出聊天室");
                        out.close();
                        in.close();
                        client.close();
                        break;
                    }
                }
    
            } catch (IOException e) { 
                e.printStackTrace();
            }
        }
    }
    
    public class MutilThreadClient { 
        public static void main(String[] args) throws IOException { 
            //根据指定ip及端口号建立连接
            Socket client = new Socket("127.0.0.1",6666);
            //启动读线程和写线程
            Thread readThread = new Thread(new ReadFromServer(client));
            Thread sendThread = new Thread(new SendMsgToServer(client));
            readThread.start();
            sendThread.start();
        }
    }

服务器：

import java.io.IOException;
    import java.io.PrintStream;
    import java.net.ServerSocket;
    import java.net.Socket;
    import java.util.Iterator;
    import java.util.Map;
    import java.util.Scanner;
    import java.util.concurrent.ConcurrentHashMap;
    import java.util.concurrent.ExecutorService;
    import java.util.concurrent.Executors;
    import java.util.regex.Matcher;
    import java.util.regex.Pattern;
    import java.util.Set;
    
    public class MutilThreadServer { 
    
        private static Map<String,Socket> clientLists = new ConcurrentHashMap<>();
        //专门用来处理每个客户端的输入，输出请求
        private static class ExecuteClientRequest implements Runnable{ 
            private Socket client;
            public ExecuteClientRequest(Socket client) { 
                this.client = client;
            }
            @Override
            public void run() { 
                try { 
                    //获取用户输入流，读取用户发来的信息
                    Scanner in = new Scanner(client.getInputStream());
                    String strFromClient = "";
                    while (true){ 
                        if (in.hasNext()){ 
                            strFromClient = in.nextLine();
                        }
                        //windows下消除用户输入自带的\r
                        Pattern pattern = Pattern.compile("\r");
                        Matcher matcher = pattern.matcher(strFromClient);
                        strFromClient = matcher.replaceAll("");
    
                        /* 注册：username:xxx * 群聊：G：群聊内容 * 私聊：P：用户名-私聊内容 * 用户退出：byebye*/
                        //注册流程
                        if (strFromClient.startsWith("username:")){ 
                            String username = strFromClient.split("\\:")[1];
                            Register(username,client);
                        }
                        //群聊流程
                        if (strFromClient.startsWith("G:")){ 
                            String groupMsg = strFromClient.split("\\:")[1];
                            groupChat(groupMsg);
                        }
                        //私聊
                        if (strFromClient.startsWith("P:")){ 
                            String username = strFromClient.split("\\:")[1].split("\\-")[0];
                            String privateMsg = strFromClient.split("\\:")[1].split("\\-")[2];
                            privateChat(username,privateMsg);
                        }
                        //用户退出：1：byebye
                        if(strFromClient.contains("byebye")){ 
                            String username = strFromClient.split("\\:")[0];
                            userOffLine(username);
                            break;
                        }
                    }
                } catch (IOException e) { 
                    e.printStackTrace();
                }
            }
            private void Register(String username,Socket socket){ 
                clientLists.put(username,socket);
                System.out.println("用户"+username+"上线了！当前聊天室人数为："+clientLists.size());
                try { 
                    PrintStream out = new PrintStream(socket.getOutputStream(),true,"UTF-8");
                    out.println("注册成功");
                    out.println("当前聊天室人数为："+clientLists.size());
                } catch (IOException e) { 
                    e.printStackTrace();
                }
            }
            //群聊——遍历map，向每个客户端输出一遍
            private void groupChat(String groupMsg) throws IOException { 
                Set<Map.Entry<String,Socket>> clientEntry = clientLists.entrySet();
                Iterator<Map.Entry<String,Socket>> iterator = clientEntry.iterator();
                while (iterator.hasNext()){ 
                    //取出每一个客户端实体
                    Map.Entry<String,Socket> client = iterator.next();
                    //拿到客户端输出流输出群聊信息
                    PrintStream out = new PrintStream(client.getValue().getOutputStream(),
                            true,"UTF-8");
                    out.println("群聊信息为："+groupMsg);
                }
    
            }
            //私聊
            private void privateChat(String username,String privateMsg) throws IOException { 
                //取出username对应的Socket
                Socket client = clientLists.get(username);
                PrintStream out = new PrintStream(client.getOutputStream(),true,"UTF-8");
                out.println("私聊信息为："+privateMsg);
            }
            private void userOffLine(String username){ 
                //删除map中的用户实体
                clientLists.remove(username);
                System.out.println("用户"+username+"已下线");
    
            }
        }
        public static void main(String[] args) throws Exception { 
            ServerSocket serverSocket = new ServerSocket(6666);
            //使用线程池来同时处理多个客户端连接
            ExecutorService executorService = Executors.newFixedThreadPool(20);
            System.out.println("等待客户端连接");
            for (int i=0;i<20;i++){ 
                Socket client = serverSocket.accept();
                System.out.println("有新的客户端连接，端口号为："+client.getPort());
                executorService.submit(new ExecuteClientRequest(client));
            }
            //关闭线程池与服务端
            executorService.shutdown();
            serverSocket.close();
        }
    }