Java SE实现多人聊天室功能

本文实例为大家分享了Java SE实现多人聊天室功能的具体代码，供大家参考，具体内容如下

实现功能：

1.实现用户注册上线，下线

2.实现群聊和私聊功能

3.实现统计当前在线人数

实现思路：

1.首先，要实现服务端与客户端之间的连接

这里是使用套接字建立TCP连接：

（1）服务器端先实例化一个描述服务器端口号的ServerSocket对象

（2）客户端要创建Socket对象来连接指定的服务器端

（3）服务器端调用ServerSocket类的accept()方法来监听连接到服务器端的客户端信息

（4）若服务器端与客户端连接成功，双方将返回一个Socket对象，此时双方可以进行通信

（5）服务器端与客户端使用I/O流进行连接，服务端的输出流连接客户端的输入流，客户端的输出流连接服务端的输入流

（6）使用close()方法关闭套接字（一定要记得关闭）

2.因为是拥有一个服务端来实现多个客户端的连接，此处还要解决的是多线程的问题。

每个客户端需要两个线程，来分别处理向服务端发送消息和向服务端接收消息

而服务端，当每增加一个客户端与服务端连接，服务端都要多创建一个线程来处理与客户端的连接

具体代码：

单线程实现：

客户端

import java.io.IOException;
import java.io.PrintStream;
import java.net.Socket;
import java.util.Scanner;

/**
 * @author LXY
 * @email 403824215@qq.com
 * @date 2018/7/20 15:46
 */
//客户端
public class SingleClient {
  public static void main(String[] args) throws IOException {
    //客户端连接服务器，返回套接字Socket对象
    Socket socket = new Socket("127.0.0.1",6666);
    //获取服务端的输出流，向服务器端输出内容
    PrintStream printStream = new PrintStream(socket.getOutputStream());
    printStream.println("我是客户端" + socket.getLocalPort());
    //获取服务器端的输入流，读取服务器端的内容
    Scanner scanner = new Scanner(socket.getInputStream());
    scanner.useDelimiter("\n");
    if(scanner.hasNext())
    {
      System.out.println(scanner.next());
    }
    //关闭流
    socket.close();
  }
}

服务端

import java.io.IOException;
import java.io.PrintStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Scanner;

/**
 * @author LXY
 * @email 403824215@qq.com
 * @date 2018/7/20 15:34
 */
//服务端
public class SingleServer {
  public static void main(String[] args) throws IOException {
    //创建服务器端的ServerSocket对象，等待客户端进行连接
    ServerSocket serverSocket = new ServerSocket(6666);
    System.out.println("服务器的端口号为6666，等待客户端连接。。。");
    //侦听并接收服务器端的连接，返回套接字Socket对象
    Socket socket = serverSocket.accept();
    //获取客户端的输入流，读取客户端的输入内容
    Scanner scanner = new Scanner(socket.getInputStream());
    scanner.useDelimiter("\n");
    if(scanner.hasNext())
    {
      System.out.println("客户端发来消息：" + scanner.next());
    }
    //获取客户端的输出流，向客户端输出内容
    PrintStream printStream = new PrintStream(socket.getOutputStream());
    printStream.println("客户端你好，我是服务器端：" + serverSocket.getLocalPort());
    //关闭流
    serverSocket.close();
  }
}

多线程实现

客户端

import java.io.IOException;
import java.io.PrintStream;
import java.net.Socket;
import java.util.Scanner;

/**
 * @author LXY
 * @email 403824215@qq.com
 * @date 2018/7/20 15:55
 */
//客户端

//客户端读取服务器端信息的线程
class ClientReadServer implements Runnable
{
  private Socket socket;

  public ClientReadServer(Socket socket)
  {
    this.socket = socket;
  }

  public void run() {
    try {
      Scanner scanner = new Scanner(socket.getInputStream());
      while (scanner.hasNext())
      {
        System.out.println(scanner.next());
      }
      socket.close();
    } catch (IOException e) {
      e.printStackTrace();
    }
  }
}

//客户端向服务端发送信息的线程
class ClientSendServer implements Runnable
{
  private Socket socket;

  public ClientSendServer(Socket socket)
  {
    this.socket = socket;
  }

  public void run() {
    try {
      PrintStream printStream = new PrintStream(socket.getOutputStream());
      Scanner scanner = new Scanner(System.in);
      while (true)
      {
        String msg = null;
        if(scanner.hasNext())
        {
          msg = scanner.next();
          printStream.println(msg);
        }
        if(msg.equals("bye"))
        {
          scanner.close();
          printStream.close();
          break;
        }
      }
    } catch (IOException e) {
      e.printStackTrace();
    }

  }
}

public class MultiClient {
  public static void main(String[] args) throws IOException {
    Socket socket = new Socket("127.0.0.1",6666);
    Thread read = new Thread(new ClientReadServer(socket));
    Thread send = new Thread(new ClientSendServer(socket));
    read.start();
    send.start();
  }
}

服务端

import java.io.IOException;
import java.io.PrintStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Map;
import java.util.Scanner;
import java.util.Set;
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;

/**
 * @author LXY
 * @email 403824215@qq.com
 * @date 2018/7/20 16:12
 */
class Server implements Runnable
{
  private static Map<String,Socket> map = new ConcurrentHashMap<String, Socket>();

  private Socket socket;

  public Server(Socket socket)
  {
    this.socket = socket;
  }

  public void run() {
    try {
      Scanner scanner = new Scanner(socket.getInputStream());
      String msg = null;
      while (true)
      {
        if(scanner.hasNextLine())
        {
          msg = scanner.nextLine();
          Pattern pattern = Pattern.compile("\r");
          Matcher matcher = pattern.matcher(msg);
          msg = matcher.replaceAll("");
          //用户注册——格式：userName:用户名
          if(msg.startsWith("userName:"))
          {
            String userName = msg.split("\\:")[1];
            userRegist(userName,socket);
            continue;
          }
          //群聊——格式：G:群聊信息
          else if(msg.startsWith("G:"))
          {
            firstStep(socket);
            String str = msg.split("\\:")[1];
            groupChat(socket,str);
            continue;
          }
          else if(msg.startsWith("P:") && msg.contains("-"))
          {
            firstStep(socket);
            String userName = msg.split("\\:")[1].split("-")[0];
            String str = msg.split("\\:")[1].split("-")[1];
            privateChat(socket,userName,str);
            continue;
          }
          else if(msg.contains("bye"))
          {
            firstStep(socket);
            userExit(socket);
            continue;
          }
          else
          {
            PrintStream printStream = new PrintStream(socket.getOutputStream());
            printStream.println("格式输入错误");
            continue;

          }
        }
      }
    } catch (IOException e) {
      e.printStackTrace();
    }

  }

  private void firstStep(Socket socket) throws IOException {
    Set<Map.Entry<String,Socket>> set = map.entrySet();
    for(Map.Entry<String,Socket> entry:set)
    {
      if(entry.getValue().equals(socket))
      {
        if(entry.getValue() == null)
        {
          PrintStream printStream = new PrintStream(socket.getOutputStream());
          printStream.println("请先进行注册操作！格式为：[userName:用户名]");
        }
      }
    }
  }

  private void userRegist(String userName, Socket socket) {
    map.put(userName,socket);
    System.out.println("用户名：" + userName + "客户端" + socket +"上线了！！");
    System.out.println("当前在线人数为" + map.size() + "人");
  }

  private void groupChat(Socket socket, String msg) throws IOException {
    Set<Map.Entry<String,Socket>> set = map.entrySet();
    String userName = null;
    for(Map.Entry<String,Socket> entry:set)
    {
      if(entry.getValue().equals(socket))
      {
        userName = entry.getKey();
        break;
      }
    }
    for(Map.Entry<String,Socket> entry:set)
    {
      Socket client = entry.getValue();
      PrintStream printStream = new PrintStream(client.getOutputStream());
      printStream.println(userName + "说" + msg);
    }
  }

  private void privateChat(Socket socket, String userName, String msg) throws IOException {
    String curUser = null;
    Set<Map.Entry<String,Socket>> set = map.entrySet();
    for(Map.Entry<String,Socket> entry:set)
    {
      if(entry.getValue().equals(socket))
      {
        curUser = entry.getKey();
        break;
      }
    }
    Socket client = map.get(userName);
    PrintStream printStream = new PrintStream(client.getOutputStream());
    printStream.println(curUser + "私聊说" + msg);
  }

  private void userExit(Socket socket) {
    String userName = null;
    for(String key:map.keySet())
    {
      if(map.get(key).equals(socket))
      {
        userName = key;
        break;
      }
    }
    map.remove(userName,socket);
    System.out.println("用户" + userName + "已下线");
  }
}

public class MultiServer {
  public static void main(String[] args) {
    try {
      ServerSocket serverSocket = new ServerSocket(6666);
      //使用线程池
      ExecutorService executorService = Executors.newFixedThreadPool(20);
      for(int i = 0;i < 20;i++)
      {
        System.out.println("欢迎来到聊天室。。。");
        Socket socket = serverSocket.accept();
        System.out.println("新人加入。。。");
        executorService.execute(new Server(socket));
      }
      executorService.shutdown();
      serverSocket.close();
    } catch (IOException e) {
      e.printStackTrace();
    }

  }
}

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