Question

所以我试图在这种情况下创建一个多线程服务器（尝试解释尽可能简单）：

一台服务器和k台客户端。
1. 服务器创建n个随机数的列表并均匀分布这些数字来自k个连接的客户端。
2. 客户计算其指定数字的平均值并将此值返回给服务器
3. 服务器等待所有值都存在并计算其间的标准差所有收到的平均值。服务器写入所有客户端的平均值以及整体屏幕上的标准偏差
4. 服务器使用不同的随机数列表重复此整个过程几次。

目前，我的客户端无法连接到服务器。我对java很新，所以请耐心等待。我如何将计算结果发送回服务器？

MultiThreadServer：

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.ArrayList;
import java.util.Random;

public class MultiThreadServer {

    public static double SendNumber;
    public static int Delay = 500;
    public static String ReceivedSum;
    public static final int PORT = 2000;

    public static void main(String[] args) throws IOException, InterruptedException {
        ServerSocket s = new ServerSocket(PORT);
        System.out.println("Server socket: " + s);
        System.out.println("Server listening...");

        try { while(true) {
            Socket socket = s.accept();
            // Blocks until a connection occurs:
            System.out.println("Connection accepted."); 
            System.out.println("The new socket: " + socket);

            DataInputStream din = new DataInputStream(socket.getInputStream());
            DataOutputStream dout = new DataOutputStream(socket.getOutputStream());
            BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

            Client t = new Client(socket);

            System.out.println("New thread started.");
            System.out.println("The new thread: " + t);
            Random r = new Random();
            for(int i=0;i<10;i++) {
                SendNumber = r.nextDouble();
                dout.writeDouble(SendNumber);
            }
            Thread.sleep(Delay);
            System.out.println("Client Sum is: " + din.read());
                }

        } //catch, while, try
        finally { s.close(); }
        } //main
    } //MultiServer

客户端：

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.InetAddress;
import java.net.Socket;
import java.util.ArrayList;
import java.util.Random;
import javafx.application.Platform;



class Client extends Thread{
    private  PrintWriter out;
    private  BufferedReader in;
    private Socket socket;
    public static ArrayList<Double> Numbers = new ArrayList<Double>();
    public static ArrayList<Client> allClients = new ArrayList<Client>();
    public static double FinalClientSum;


    public Client(Socket s) throws IOException {
        socket = s;
        in = new BufferedReader(
                new InputStreamReader(socket.getInputStream()));
        out = new PrintWriter(
                new BufferedWriter(
                        new OutputStreamWriter(socket.getOutputStream())), true);

        String line;
        while((line = in.readLine()) != null) {
            Numbers.add((Double.parseDouble(line)));
        }
        synchronized(this) {
            allClients.add(this);
        }

        start();
    }

    public void run(){
            try {

                DataInputStream din = new DataInputStream(socket.getInputStream());
                DataOutputStream dout = new DataOutputStream(socket.getOutputStream());

                BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
                for(int i = 0; i<Numbers.size();i++) {
                    FinalClientSum += Numbers.get(i); //calc sum
                }
                //send back the information to server.
                dout.writeDouble(FinalClientSum);

            }catch(Exception e) {

            }finally {
                try { socket.close(); }
                catch(IOException e) {
                    System.out.println("Client thread " +  ": Socket not closed!");
                }
                synchronized(this) {
                    allClients.remove(allClients.indexOf(this));
                }
        }

    }
}

Answer 1

你的Socket socket = s.accept();应该进入while循环。

向客户端发送消息并将结果发送回服务器

1 个答案: