如何使用客户端机器的 Java 套接字在服务器机器上创建目录？

Question

I'm writing a client server application in Java. At one point I need my PC client to create a directory on my PC server via socket, only I could not make it happen. Can someone help me?

Answer 1

You need to design a communication protocol , this is a type of dialect in which your server and your client speak.

i have designed the simplest communication protocol ever for you, that only has 2 commands.

Consist in 2 simple commands and its meaning:

mkdir - create a directory in the remote server

exit - close the session

this means that you have to write 2 programs (server and client) that implement your great communication protocol.

you can start from this code that actually sends/receives 2 commands and pretend executing the command and close the session.

Server side:

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

public class Server
{
    static ServerSocket   serverSocket;
    static Socket         socket;
    static BufferedWriter writer;
    static BufferedReader reader;

    public static void main(String args[])
    {
        try
        {
            System.out.println("Hola mundo");
            serverSocket = new ServerSocket(12345);
            socket = serverSocket.accept();
            reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            writer = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
            while(true)
            {
                String command = reader.readLine();
                if(command.contains("mkdir"))
                {
                    System.out.println("Creating a new directory " + command);
                    // put yoour code to create a directory with the params
                }
                else if(command.equals("exit"))
                {
                    System.out.println("Exiting the program");
                    break;
                }
            }
        }
        catch(Exception err)
        {

        }
    }
}

Client side :

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

public class Client
{
    static Socket socket;
    static BufferedWriter writer;
    static BufferedReader reader;
    public static void main(String args[])
    {
        try
        {
            System.out.println("Connecting to the server");
            InetSocketAddress address = new InetSocketAddress("127.0.0.1", 12345);
            socket = new Socket();
            socket.connect(address);
            reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            writer = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));

            // creating folder
            System.out.println("Creating remote folder");
            writer.write("mkdir newFolder\r\n");
            writer.flush();


            // closing server
            System.out.println("Sending exit command");
            writer.write("exit\r\n");
            writer.flush();

            socket.close();
        }
        catch(IOException err)
        {
            System.out.println(err.getMessage());
        }
    }
}

Now your challenge is to make really the folder is created when the mkdir command reaches the server.

Compilation:

javac Client.java

javac Server.java

Answer 2

On the server, you can use Files#createDirectory() to create a directory on the filesystem. You might use data passed by the client to determine the name of the directory.

Here's a link to the Javadoc: https://docs.oracle.com/javase/8/docs/api/java/nio/file/Files.html#createDirectory-java.nio.file.Path-java.nio.file.attribute.FileAttribute...-

Here's a link in Oracle's Java Tutorials that includes an example: https://docs.oracle.com/javase/tutorial/essential/io/dirs.html#create