Java Socket聊天代码（支持群聊，server负责转发，可连接多个client，附带.bat启动程序）

import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.io.PrintWriter; import java.net.ServerSocket; import java.net.Socket; import java.util.ArrayList; import java.util.List; public class ChatServer { public static void start(int port){ try { ServerSocket server = new ServerSocket(port); List<Socket> clients = new ArrayList<Socket>(); System.out.println("聊天室创建成功，等待成员加入！"); Socket client = null; while(true){ client = server.accept(); clients.add(client); //加入客户端列表 //创建一个监听线程，接受客户端的消息并转发 new ServerListener(client, clients).start(); System.out.println("聊天室在线人数："+clients.size()); } } catch (IOException e) { System.out.println("聊天室服务创建失败!"); e.printStackTrace(); } } public static void main(String[] args) { ChatServer.start(Integer.parseInt(args[0])); //启动聊天服务 } } class ServerListener extends Thread{ private Socket client; private List<Socket> clients; public ServerListener(Socket client, List<Socket> clients) { this.client = client; this.clients = clients; } @Override public void run() { BufferedReader br = null; PrintWriter pw = null; PrintWriter clientspw = null; if(!client.isClosed()&&client.isConnected()){ try { br = new BufferedReader(new InputStreamReader(client.getInputStream())); pw = new PrintWriter(client.getOutputStream()); String welcome = "欢迎"+client.getInetAddress().getHostName()+"加入聊天室！"; System.out.println(welcome); pw.println(welcome); pw.flush(); while(true){ if(!client.isClosed()&&client.isConnected()){ String message = client.getInetAddress().getHostName() + " 说：" + br.readLine(); //读取用户发来的消息 System.out.println(message); for(Socket s : clients){ if(!client.getInetAddress().getHostAddress().equals(s.getInetAddress().getHostAddress())){ clientspw = new PrintWriter(s.getOutputStream()); clientspw.println(message); clientspw.flush(); } } } else{ clients.remove(client); } } } catch (IOException ie) { System.out.println("用户"+client.getInetAddress().getHostName()+"退出聊天室！"); try{ for(Socket s : clients){ if(!client.getInetAddress().getHostAddress().equals(s.getInetAddress().getHostAddress())){ clientspw = new PrintWriter(s.getOutputStream()); clientspw.println("用户"+client.getInetAddress().getHostName()+"退出聊天室！"); clientspw.flush(); } } }catch(IOException e){ e.printStackTrace(); } clients.remove(client); } finally{ try { if(br!=null) br.close(); if(pw!=null) pw.close(); } catch (IOException e) { e.printStackTrace(); } } }else{ clients.remove(client); } } }