我可以使用我的 java 程序打开一个关闭的端口吗?

Can I open a closed port using my java program?

我试过这个来听打开端口..

public class PortCheck {

    public static void main(String[] args) {
        try {
            Socket socket = new Socket("localhost",4500);

            System.out.println("port open");
        } catch (IOException e) {
            System.out.println("not open");
        }
    }
}

但是我想从我的 java program.Is 打开一个关闭的端口,有什么办法吗?

Socket is a client socket for connecting to a server. To open a listening socket to accept clients, you need to use ServerSocket 相反,如果端口尚未打开,它将打开一个端口,如果端口已被使用,它将失败。

public class PortCheck {

    public static void main(String[] args) {
        try {
            ServerSocket socket = new ServerSocket(4500, 0, InetAddress.getLocalHost());
            System.out.println("port available");
        } catch (IOException e) {
            System.out.println("port not available");
        }
    }
}