Java多线程客户端服务器：等待指定客户端数后启动线程实现消息广播

我把你写的多线程客户端-服务器聊天应用代码按规范整理好了哈～这个应用最多支持2个客户端连接，客户端得先验证密码才能加入，等连接数到上限后，服务器就会给每个客户端开个线程，专门处理消息读取和广播给其他在线客户端：

import java.io.DataInputStream;
import java.io.PrintStream;
import java.io.IOException;
import java.net.Socket;
import java.net.ServerSocket;
/*
 * A chat server that delivers public and private messages.
 */
public class Server_X_Client {
 // The server socket.
 private static ServerSocket serverSocket = null;
 // The client socket.
 private static Socket clientSocket = null;
 // This chat server can accept up to maxClientsCount clients' connections.
 private static final int numOfClients = 2;
 private static final clientThread[] threads = new clientThread[numOfClients];
 private static final Socket[] sockets = new Socket [numOfClients];
 public static void main(String args[]) throws InterruptedException {
 // The default port number.
 int portNumber = 2222;
 int count=0;
 /*
 * Open a server socket on the portNumber (default 2222). Note that we can
 * not choose a port less than 1023 if we are not privileged users (root).
 */
 try {
 serverSocket = new ServerSocket(portNumber);
 } catch (IOException e) {
 System.out.println(e);
 }
 /*
 * Create a client socket for each connection and pass it to a new client
 * thread.
 */
 while (true) {
 try {
 clientSocket = serverSocket.accept();
 int i = 0;
 for (i = 0; i < numOfClients; i++) {
 if (sockets[i] == null) {
 PrintStream os = new PrintStream(clientSocket.getOutputStream());
 DataInputStream in = new DataInputStream (clientSocket.getInputStream());
 os.println("Enter your name: ");
 String name = in.readLine().trim();
 os.println("Enter server password: ");
 String psw = in.readLine().trim();
 if(psw.equals("Pelin")){
 os.println("Password is correct+ "+ i+" pls wait..");
 sockets[i] = clientSocket;
 }else{
 os.println("Password is wrong..");
 }
 break;
 }
 }
 if (i == numOfClients-1) {
 for (int j=0;j<numOfClients;j++){
 if(threads[j]==null){
 (threads[j] = new clientThread(sockets[j], threads)).start();
 //threads[j].join();
 }
 }
 }
 } catch (IOException e) {
 System.out.println(e);
 }
 }
 }
}
/*
 * The chat client thread. This client thread opens the input and the output
 * streams for a particular client, ask the client's name, informs all the
 * clients connected to the server about the fact that a new client has joined
 * the chat room, and as long as it receive data, echos that data back to all
 * other clients. When a client leaves the chat room this thread informs also
 * all the clients about that and terminates.
 */
class clientThread extends Thread {
 private DataInputStream is = null;
 private PrintStream os = null;
 private Socket clientSocket = null;
 private clientThread[] threads;
 private int maxClientsCount;
 public clientThread(Socket clientSocket, clientThread[] threads) {
 this.clientSocket = clientSocket;
 this.threads = threads;
 maxClientsCount = threads.length;
 }
 public void run() {
 int maxClientsCount = this.maxClientsCount;
 clientThread[] threads = this.threads;
 try {
 /*
 * Create input and output streams for this client.
 */
 is = new DataInputStream(clientSocket.getInputStream());
 os = new PrintStream(clientSocket.getOutputStream());
 for (int i = 0; i < maxClientsCount; i++) {
 if (threads[i] != null && threads[i] != this) {
 threads[i].os.println("READY!!");
 }
 }
 while (true) {
 String line = is.readLine();
 if (line.startsWith("/quit")) {
 break;
 }
 for (int i = 0; i < maxClientsCount; i++) {
 if (threads[i] != null) {
 threads[i].os.println("Someone:" + line);
 }
 }
 }
 for (int i = 0; i < maxClientsCount; i++) {
 if (threads[i] != null && threads[i] != this) {
 threads[i].os.println("*** The user " +"XXX" + " is leaving the chat room !!! ***");
 }
 }
 os.println("*** Bye "+" ***");
 /*
 * Clean up. Set the current thread variable to null so that a new client
 * could be accepted by the server.
 */
 for (int i = 0; i < maxClientsCount; i++) {
 if (threads[i] == this) {
 threads[i] = null;
 }
 }
 /*
 * Close the output stream, close the input stream, close the socket.
 */
 is.close();
 os.close();
 clientSocket.close();
 } catch (IOException e) {
 }
 }
}

import java.io.DataInputStream;
import java.io.PrintStream;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.Scanner;
public class NetworkClient implements Runnable {
 // The client socket
 private static Socket clientSocket = null;
 // The output stream
 private static PrintStream os = null;
 // The input stream
 private static DataInputStream is = null;
 private static BufferedReader inputLine = null;
 private static boolean closed = false;
 public static void main(Str

内容的提问来源于stack exchange，提问作者joy_jlee