编写程序，客户端发送一个文件名给服务器，服务器查找本地磁盘，如果文件存在，则把文件内容发送个客户端，否则回答文件不存在

import java.io.*; import java.net.*; public class SimplifiedServer { private static final int PORT = 12345; public static void main(String[] args) { try (ServerSocket serverSocket = new ServerSocket(PORT)) { System.out.println("服务器在在接收指令" + PORT); while (true) { Socket socket = serverSocket.accept(); handleClient(socket); } } catch (IOException e) { e.printStackTrace(); } } private static void handleClient(Socket socket) { new Thread(() -> { try ( BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream())); PrintWriter out = new PrintWriter(socket.getOutputStream(), true); ) { String fileName = in.readLine(); File file = new File(fileName); if (file.exists()) { try (BufferedReader fileReader = new BufferedReader(new FileReader(file))) { String line; while ((line = fileReader.readLine()) != null) { out.println(line); } } } else { out.println("文件未找到"); } } catch (IOException e) { e.printStackTrace(); } finally { try { socket.close(); } catch (IOException e) { // Ignore } } }).start(); } }