Apakah alat komunikasi rangkaian biasa yang disertakan dalam perpustakaan fungsi Java?

// 客户端
import java.net.*;

public class SocketClient {

    public static void main(String[] args) throws Exception {
        // 创建 Socket 并连接到服务器
        Socket socket = new Socket("localhost", 8080);

        // 获取输出流并发送消息
        DataOutputStream out = new DataOutputStream(socket.getOutputStream());
        out.writeUTF("Hello from client!");

        // 关闭输出流和 Socket
        out.close();
        socket.close();
    }
}

// 服务器
import java.net.*;

public class SocketServer {

    public static void main(String[] args) throws Exception {
        // 创建 ServerSocket 并侦听连接
        ServerSocket serverSocket = new ServerSocket(8080);

        while (true) {
            // 接受客户端连接
            Socket clientSocket = serverSocket.accept();

            // 获取输入流并读取消息
            DataInputStream in = new DataInputStream(clientSocket.getInputStream());
            String message = in.readUTF();

            System.out.println("Received message: " + message);

            // 关闭输入流和 Socket
            in.close();
            clientSocket.close();
        }
    }
}

// 服务器
import java.net.*;
import java.nio.*;
import java.nio.channels.*;

public class NonBlockingServerSocket {

    public static void main(String[] args) throws Exception {
        // 创建 ServerSocketChannel 并绑定到端口
        ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
        serverSocketChannel.bind(new InetSocketAddress(8080));
        serverSocketChannel.configureBlocking(false);

        // 创建 Selector 并注册 ServerSocketChannel
        Selector selector = Selector.open();
        serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);

        while (true) {
            // 侦听可用的选择键
            int readyKeys = selector.select();

            if (readyKeys == 0) {
                continue;
            }

            // 处理可用的选择键
            Iterator<SelectionKey> keys = selector.selectedKeys().iterator();
            while (keys.hasNext()) {
                SelectionKey key = keys.next();
                keys.remove();

                // 处理可接受的键
                if (key.isAcceptable()) {
                    SocketChannel clientSocketChannel = serverSocketChannel.accept();
                    clientSocketChannel.configureBlocking(false);
                    clientSocketChannel.register(selector, SelectionKey.OP_READ);
                }

                // 处理可读的键
                else if (key.isReadable()) {
                    // ...
                }
            }
        }
    }
}