Swift Network.framework Study 2019 1206 "Server TCP" Part 2 Use receive method

Study

Network.framework Study: Server side

environment

Client：Java、NetBeans Server：Swift、Xcode

Client Source Java

package example.java.network;

import java.io.PrintWriter;
import java.net.Socket;

public class ExampleClientSocket {
    public static void main(String[] args) {
        try(Socket socket = new Socket("localhost", 7777);
            PrintWriter printWriter = new PrintWriter(socket.getOutputStream(), true);) {
            printWriter.println("Example Send Data");
        }
        catch(Exception e) {
            System.out.println(e);
        }
    }
}

Server Source Swift

Use NWLister Receive processing registration and start execution in NWConnection after connection establishment Use the receive method that can specify the number of received bytes. The maximum length of several minutes was acquired from one received data. In the example below, it is 5 bytes. Even if you send 5 bytes or more, it seems that reception is not called continuously after the 6th byte. We are investigating whether we can continue.

main.swift

import Foundation
import Network

var networkServer = NetworkServer()

networkServer.startListener()

while networkServer.running {
    sleep(1)
}

NetworkServer.swift

import Foundation
import Network

class NetworkServer {
    public var running = true

    func startListener() {
        let myQueue = DispatchQueue(label: "ExampleNetwork")

        do {
            let nWListener = try NWListener(using: .tcp, on: 7777)
            nWListener.newConnectionHandler = { (newConnection) in
                print("New Connection!!")
                newConnection.receive(minimumIncompleteLength: 1, maximumLength: 5, completion: { (data, context, flag, error) in
                    print("receiveMessage")
                    let receiveData = [UInt8](data!)
                    print(receiveData)
                })
                newConnection.start(queue: myQueue)
            }
            nWListener.start(queue: myQueue)
            print("start")
        }
        catch {
            print(error)
        }
    }
}