Java语言实现配置服务端端口号，开始进行电子 点名，等待学生端发送个人信息，将收到信息显示在学生名单中，点名结束后关 闭服务端服务。学生信息显示要求：学号 姓名 ip，每行表示一个学生。“导出 文件“实现将本次点名数据保存至数据库

要实现这个功能，可以采用Java中的Socket编程实现服务端和客户端之间的通信。具体步骤如下：

1. 服务端实现：在服务端，先创建一个ServerSocket对象，指定端口号，然后使用accept()方法监听客户端请求，一旦有客户端连接，就创建一个线程处理该客户端的请求。在线程中，可以使用InputStream读取客户端发送的信息，然后将信息显示在学生名单中。

2. 学生信息显示：在学生名单中，可以用一个列表来存储每个学生的信息。当收到一个学生的信息后，可以将其加入到列表中，并且更新显示。

3. 导出文件：在程序结束时，可以将学生名单中的数据保存到数据库中。可以使用JDBC连接数据库，并执行INSERT语句将数据插入到相应的表中。

下面是一个简单的示例代码，仅供参考：

服务端代码：

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

public class Server {
    private ServerSocket serverSocket;
    private List<String> studentList = new ArrayList<String>();

    public Server(int port) throws IOException {
        serverSocket = new ServerSocket(port);
        System.out.println("Server started on port " + port);
    }

    public void start() throws IOException {
        while (true) {
            Socket clientSocket = serverSocket.accept();
            System.out.println("Client connected from " + clientSocket.getInetAddress().getHostAddress());
            new ClientHandler(clientSocket).start();
        }
    }

    public void addStudent(String student) {
        synchronized(studentList) {
            studentList.add(student);
        }
    }

    public void exportData() throws SQLException {
        Connection conn = DriverManager.getConnection("jdbc:mysql://localhost/test", "root", "");
        Statement stmt = conn.createStatement();
        for (String student : studentList) {
            String[] fields = student.split(",");
            String sql = "INSERT INTO students (id, name, ip) VALUES ('" + fields[0] + "', '" + fields[1] + "', '" + fields[2] + "')";
            stmt.executeUpdate(sql);
        }
        stmt.close();
        conn.close();
    }

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

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

        public void run() {
            try {
                out = new PrintWriter(clientSocket.getOutputStream(), true);
                in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
                String inputLine;
                while ((inputLine = in.readLine()) != null) {
                    addStudent(inputLine);
                    System.out.println("Received student info: " + inputLine);
                }
            } catch (IOException e) {
                System.out.println("Error handling client: " + e.getMessage());
            } finally {
                try {
                    if (in != null) in.close();
                    if (out != null) out.close();
                    clientSocket.close();
                } catch (IOException e) {
                    System.out.println("Error closing client connection: " + e.getMessage());
                }
            }
        }
    }

    public static void main(String[] args) {
        int port = 1234;
        try {
            Server server = new Server(port);
            server.start();
            server.exportData();
        } catch (IOException e) {
            System.out.println("Error starting server: " + e.getMessage());
        } catch (SQLException e) {
            System.out.println("Error exporting data: " + e.getMessage());
        }
    }
}

客户端代码：

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

public class Client {
    private Socket socket;
    private PrintWriter out;
    private BufferedReader in;

    public Client(String host, int port) throws UnknownHostException, IOException {
        socket = new Socket(host, port);
        out = new PrintWriter(socket.getOutputStream(), true);
        in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
    }

    public void sendInfo(String info) {
        out.println(info);
    }

    public void close() throws IOException {
        if (in != null) in.close();
        if (out != null) out.close();
        socket.close();
    }

    public static void main(String[] args) {
        String host = "localhost";
        int port = 1234;
        try {
            Client client = new Client(host, port);
            client.sendInfo("001,张三,192.168.0.1");
            client.sendInfo("002,李四,192.168.0.2");
            client.close();
        } catch (IOException e) {
            System.out.println("Error connecting to server: " + e.getMessage());
        }
    }
}