java Socket实现多人群聊与私聊功能

import java.io.*;
import java.net.*;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.ThreadPoolExecutor;
 
 
public class TCPServer { 
 
 private ServerSocket serverSocket;
 
 /**
 * 创建线程池来管理客户端的连接线程
 * 避免系统资源过度浪费
 */
 private ExecutorService exec;
 
 // 存放客户端之间私聊的信息
 private Map<String,PrintWriter> storeInfo;
 
 public TCPServer() {
 try {
 
 serverSocket = new ServerSocket(6789);
 storeInfo = new HashMap<String, PrintWriter>();
 exec = Executors.newCachedThreadPool();
 
 } catch (Exception e) {
 e.printStackTrace();
 }
 }
 
 // 将客户端的信息以Map形式存入集合中
 private void putIn(String key,PrintWriter value) {
 synchronized(this) {
 storeInfo.put(key, value);
 }
 }
 
 // 将给定的输出流从共享集合中删除
 private synchronized void remove(String key) {
 storeInfo.remove(key);
 System.out.println("当前在线人数为："+ storeInfo.size());
 }
 
 // 将给定的消息转发给所有客户端
 private synchronized void sendToAll(String message) {
 for(PrintWriter out: storeInfo.values()) {
 out.println(message);
 }
 }
 
 // 将给定的消息转发给私聊的客户端
 private synchronized void sendToSomeone(String name,String message) {
 PrintWriter pw = storeInfo.get(name); //将对应客户端的聊天信息取出作为私聊内容发送出去
 if(pw != null) pw.println(message); 
 }
 
 public void start() {
 try {
 while(true) {
 System.out.println("等待客户端连接... ... ");
 Socket socket = serverSocket.accept();
 
 // 获取客户端的ip地址
 InetAddress address = socket.getInetAddress();
 System.out.println("客户端：“" + address.getHostAddress() + "”连接成功！ ");
 /**
 * 启动一个线程，由线程来处理客户端的请求，这样可以再次监听
 * 下一个客户端的连接
 */
 exec.execute(new ListenrClient(socket)); //通过线程池来分配线程
 }
 } catch(Exception e) {
 e.printStackTrace();
 }
 }
 
 /**
 * 该线程体用来处理给定的某一个客户端的消息，循环接收客户端发送
 * 的每一个字符串，并输出到控制台
 */
 class ListenrClient implements Runnable {
 
 private Socket socket;
 private String name;
 
 public ListenrClient(Socket socket) {
 this.socket = socket;
 }
 
 // 创建内部类来获取昵称
 private String getName() throws Exception {
 try {
 //服务端的输入流读取客户端发送来的昵称输出流
 BufferedReader bReader = new BufferedReader(
 new InputStreamReader(socket.getInputStream(), "UTF-8"));
 //服务端将昵称验证结果通过自身的输出流发送给客户端
 PrintWriter ipw = new PrintWriter(
 new OutputStreamWriter(socket.getOutputStream(), "UTF-8"),true);
 
 //读取客户端发来的昵称
 while(true) {
 String nameString = bReader.readLine();
 if ((nameString.trim().length() == 0) || storeInfo.containsKey(nameString)) {
 ipw.println("FAIL");
 } else {
 ipw.println("OK");
 return nameString;
 }
 }
 } catch(Exception e) {
 throw e;
 }
 }
 
 @Override 
 public void run() {
 try {
 /*
 * 通过客户端的Socket获取客户端的输出流
 * 用来将消息发送给客户端
 */
 PrintWriter pw = new PrintWriter(
 new OutputStreamWriter(socket.getOutputStream(), "UTF-8"), true);
 
 /*
 * 将客户昵称和其所说的内容存入共享集合HashMap中
 */
 name = getName();
 putIn(name, pw);
 Thread.sleep(100);
 
 // 服务端通知所有客户端，某用户上线
 sendToAll("[系统通知] “" + name + "”已上线");
 
 /*
 * 通过客户端的Socket获取输入流
 * 读取客户端发送来的信息
 */
 BufferedReader bReader = new BufferedReader(
 new InputStreamReader(socket.getInputStream(), "UTF-8"));
 String msgString = null;
 
 
 while((msgString = bReader.readLine()) != null) {
 // 检验是否为私聊（格式：@昵称：内容）
 if(msgString.startsWith("@")) {
 int index = msgString.indexOf(":");
 if(index >= 0) {
 //获取昵称
 String theName = msgString.substring(1, index);
 String info = msgString.substring(index+1, msgString.length());
 info = name + "："+ info;
 //将私聊信息发送出去
 sendToSomeone(theName, info);
 continue;
 }
 }
 // 遍历所有输出流，将该客户端发送的信息转发给所有客户端
 System.out.println(name+"："+ msgString);
 sendToAll(name+"："+ msgString);
 } 
 } catch (Exception e) {
 // e.printStackTrace();
 } finally {
 remove(name);
 // 通知所有客户端，某某客户已经下线
 sendToAll("[系统通知] "+name + "已经下线了。");
 
 if(socket!=null) {
 try {
 socket.close();
 } catch(IOException e) {
 e.printStackTrace();
 }
 } 
 }
 }
 }
 
 public static void main(String[] args) {
 TCPServer server = new TCPServer();
 server.start();
 }
}

import java.io.*;
import java.net.*;
import java.util.Scanner;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.ThreadPoolExecutor;
 
public class TCPClient {
 
 static private Socket clientSocket;
 
 public TCPClient() {}
 
 public static void main(String[] args) throws Exception {
 Scanner scanner = new Scanner(System.in);
 String serverIP;
 
 System.out.println("请设置服务器IP：");
 serverIP = scanner.next();
 clientSocket = new Socket(serverIP, 6789);
 TCPClient client = new TCPClient();
 client.start();
 }
 
 public void start() {
 try {
 Scanner scanner = new Scanner(System.in);
 setName(scanner);
 
 // 接收服务器端发送过来的信息的线程启动
 ExecutorService exec = Executors.newCachedThreadPool();
  exec.execute(new ListenrServser());
 
 // 建立输出流，给服务端发信息
 PrintWriter pw = new PrintWriter(
 new OutputStreamWriter(clientSocket.getOutputStream(), "UTF-8"), true);
 
 while(true) {
 pw.println(scanner.nextLine());
 }
 } catch(Exception e) {
 e.printStackTrace();
 } finally {
 if (clientSocket !=null) {
 try {
 clientSocket.close();
 } catch(IOException e) {
 e.printStackTrace();
 }
 }
 }
 }
 
 private void setName(Scanner scan) throws Exception {
 String name;
 //创建输出流
 PrintWriter pw = new PrintWriter(
 new OutputStreamWriter(clientSocket.getOutputStream(), "UTF-8"),true);
 //创建输入流
 BufferedReader br = new BufferedReader(
 new InputStreamReader(clientSocket.getInputStream(),"UTF-8"));
 
 while(true) { 
 System.out.println("请创建您的昵称：");
 name = scan.nextLine();
 if (name.trim().equals("")) {
 System.out.println("昵称不得为空");
 } else { 
 pw.println(name);
 String pass = br.readLine();
 if (pass != null && (!pass.equals("OK"))) {
 System.out.println("昵称已经被占用，请重新输入：");
 } else {
 System.out.println("昵称“"+name+"”已设置成功，可以开始聊天了");
 break;
 }
 }
 }
 }
 
 // 循环读取服务端发送过来的信息并输出到客户端的控制台
 class ListenrServser implements Runnable {
 
 @Override
 public void run() {
 try {
 BufferedReader br = new BufferedReader(
 new InputStreamReader(clientSocket.getInputStream(), "UTF-8"));
 String msgString;
 while((msgString = br.readLine())!= null) {
 System.out.println(msgString);
 }
 } catch(Exception e) {
 e.printStackTrace();
 }
 }
 }
 
}