Swift Network.framework Study 20191203

Study

Network.framework Study: Client side

environment

Client：Swift、Xcode Server：Java、NetBeans

Client Source Swift

import Foundation
import Network

func startConnection() {
    let myQueue = DispatchQueue(label: "ExampleNetwork")
    let connection = NWConnection(host: "localhost", port: 7777, using: NWParameters.tcp)
    connection.stateUpdateHandler = { (newState) in
        switch(newState) {
        case .ready:
            print("ready")
            sendMessage(connection)
        case .waiting(let error):
            print("waiting")
            print(error)
        case .failed(let error):
            print("failed")
            print(error)
        default:
            print("defaults")
            break
        }
    }
    connection.start(queue: myQueue)
}

func sendMessage(_ connection: NWConnection) {
    let data = "Example Send Data".data(using: .utf8)
    let completion = NWConnection.SendCompletion.contentProcessed { (error: NWError?) in
        print("send completely")
    }
    connection.send(content: data, completion: completion)
}

startConnection()

while true {
    sleep(1)
}

The last loop is awkward.

Server Source Java

package example.java.network;

import java.net.ServerSocket;
import java.net.Socket;
import java.util.Scanner;

public class ExampleServerSocket {
    public static void main(String[] args) {
        try {
            ServerSocket serverSocket = new ServerSocket(7777);
            System.out.println("socket create");
            Socket socket = serverSocket.accept();
            System.out.println("accept");
            Scanner scanner = new Scanner(socket.getInputStream());
            while(scanner.hasNext() == true) {
                System.out.println(scanner.nextLine());
            }
        }
        catch(Exception e) {
            System.out.println(e);
        }
    }
}

I forgot the Scanner hasNext () condition after a long time. I have to check and improve.