使用DataOutputStream，DataInputStream完成Java的Socket编程

Java Socket编程是一种网络编程，可以使用DataOutputStream和DataInputStream类来实现数据的读写和传输。以下是使用DataOutputStream和DataInputStream完成Java Socket编程的步骤：

1. 创建一个ServerSocket对象，指定端口号并监听客户端连接请求：

ServerSocket serverSocket = new ServerSocket(8080);
Socket socket = serverSocket.accept();

2. 使用Socket对象获取DataOutputStream和DataInputStream对象：

DataOutputStream dos = new DataOutputStream(socket.getOutputStream());
DataInputStream dis = new DataInputStream(socket.getInputStream());

3. 使用DataOutputStream向客户端发送数据：

dos.writeUTF("Hello, client!");

4. 使用DataInputStream从客户端接收数据：

String message = dis.readUTF();

5. 关闭Socket连接和流资源：

dis.close();
dos.close();
socket.close();
serverSocket.close();

完整代码示例：

Server端：

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.net.ServerSocket;
import java.net.Socket;

public class Server {
    public static void main(String[] args) throws Exception {
        ServerSocket serverSocket = new ServerSocket(8080);
        System.out.println("Server started.");
        Socket socket = serverSocket.accept();
        System.out.println("Client connected.");

        DataOutputStream dos = new DataOutputStream(socket.getOutputStream());
        DataInputStream dis = new DataInputStream(socket.getInputStream());

        dos.writeUTF("Hello, client!");
        String message = dis.readUTF();
        System.out.println("Received message from client: " + message);

        dis.close();
        dos.close();
        socket.close();
        serverSocket.close();
    }
}

Client端：

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.net.Socket;

public class Client {
    public static void main(String[] args) throws Exception {
        Socket socket = new Socket("localhost", 8080);
        System.out.println("Connected to server.");

        DataOutputStream dos = new DataOutputStream(socket.getOutputStream());
        DataInputStream dis = new DataInputStream(socket.getInputStream());

        String message = dis.readUTF();
        System.out.println("Received message from server: " + message);
        dos.writeUTF("Hello, server!");

        dis.close();
        dos.close();
        socket.close();
    }
}