Java编写一个测试应用程序，作为聊天服务器（ip:192.168.1.1，端口：8888），等待来自多个客户端的连接请求，通信应该通过多线程使用TCP协议来处理连接。

以下是一个简单的Java程序，可以作为聊天服务器，等待来自多个客户端的连接请求。程序使用多线程和TCP协议来处理连接，可以同时与多个客户端进行通信。你可以将该程序保存为ChatServer.java文件，并在命令行中运行它。

import java.io.*;
import java.net.*;

public class ChatServer {
    public static void main(String[] args) {
        try (ServerSocket serverSocket = new ServerSocket(8888)) {
            System.out.println("Chat server is running on port 8888...");
            while (true) {
                Socket clientSocket = serverSocket.accept();
                System.out.println("Accepted connection from " + clientSocket);
                ClientHandler clientHandler = new ClientHandler(clientSocket);
                clientHandler.start();
            }
        } catch (IOException e) {
            System.out.println("Error starting the chat server: " + e.getMessage());
        }
    }
}

class ClientHandler extends Thread {
    private Socket clientSocket;
    private BufferedReader in;
    private PrintWriter out;

    public ClientHandler(Socket socket) {
        this.clientSocket = socket;
    }

    public void run() {
        try {
            in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
            out = new PrintWriter(clientSocket.getOutputStream(), true);         
            out.println("Welcome to the chat server!");
            while (true) {
                String inputLine = in.readLine();
                if (inputLine == null) break;
                System.out.println("Received message from " + clientSocket + ": " + inputLine);
                out.println("You said: " + inputLine);
            }
        } catch (IOException e) {
            System.out.println("Error handling client: " + e.getMessage());
        } finally {
            try {
                clientSocket.close();
            } catch (IOException e) {
                System.out.println("Error closing client socket: " + e.getMessage());
            }
        }
    }
}

该程序会监听端口8888，等待客户端连接请求。当客户端连接时，程序会为每个客户端启动一个新的线程（ClientHandler），与客户端进行通信。

客户端可以使用以下代码连接到聊天服务器：

import java.io.*;
import java.net.*;

public class ChatClient {
    public static void main(String[] args) {
        try (Socket socket = new Socket("192.168.1.1", 8888);
             BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
             PrintWriter out = new PrintWriter(socket.getOutputStream(), true)) {
            System.out.println("Connected to the chat server!");
            BufferedReader console = new BufferedReader(new InputStreamReader(System.in));
            while (true) {
                String inputLine = console.readLine();
                if (inputLine == null || inputLine.equals("quit")) break;
                out.println(inputLine);
                String response = in.readLine();
                System.out.println("Server response: " + response);
            }
        } catch (IOException e) {
            System.out.println("Error connecting to the chat server: " + e.getMessage());
        }
    }
}

在命令行中运行ChatClient.java，你可以与聊天服务器进行通信。当你输入一条消息并按下回车键时，消息将被发送到服务器，并显示服务器的响应。如果你想退出聊天室，请输入“quit”。