Question

我试图创建一个简单的Java Chatting应用程序，但遇到了一些问题。

以下是我的代码，用于两个类：

Serveur.java：

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

class Serveur{

    private String msgClient, msgServeur;
    private ServerSocket serverSocket;
    private DataOutputStream out;
    private Socket socket;
    private int port;
    private BufferedReader in;

    public Serveur() throws IOException{
        System.out.println("Serveur OK...");
        this.port = 21;
        this.serverSocket = new ServerSocket(this.port);
        while(true){
            this.socket = serverSocket.accept();
            this.in = new BufferedReader(new InputStreamReader(this.socket.getInputStream()));
            this.out = new DataOutputStream(this.socket.getOutputStream());
            this.msgClient = this.in.readLine();
            System.out.println("Received: " + this.msgClient);
            this.msgServeur = this.msgClient.toUpperCase() + '\n';
            send(this.msgServeur);
        }
    }

    public void send(String msg) throws IOException{
        this.out.writeBytes(msg);
    }

    public static void main(String argv[]) throws Exception {
        Serveur serveur = new Serveur();
    }
}

Client.java：

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

class Client{

    private String sentence;
    private String modifiedSentence;
    private int port;
    private BufferedReader inUser;
    private BufferedReader inServeur;
    private Socket socket;
    private DataOutputStream out;

    public Client() throws UnknownHostException, IOException{
        this.sentence = "";
        this.modifiedSentence = "";
        this.port = 21;
        this.inUser = new BufferedReader(new InputStreamReader(System.in));
        this.socket = new Socket("localhost", this.port);
        this.out = new DataOutputStream(this.socket.getOutputStream());
        this.inServeur = new BufferedReader(new InputStreamReader(this.socket.getInputStream()));
        sentence = this.inUser.readLine();
        this.out.writeBytes(sentence + '\n');
        modifiedSentence = this.inServeur.readLine();
        System.out.println("FROM SERVER: " + modifiedSentence);
        this.socket.close();
    }

    public static void main(String argv[]) throws Exception{
        Client client = new Client();
    }
}

我有两个问题：
- 客户端发送消息，服务器以大写形式返回相同的消息。如何在不立即关闭套接字连接的情况下允许客户端发送消息？ - 服务器看起来没问题，但是当我有多个客户端时，是否会有多个连接客户端发生变化？我如何向特定客户广播消息和消息？

Answer 1

客户端发送消息，服务器返回相同的消息大写。我如何允许客户端发送无限消息和发送第一条消息后不要破坏自己吗？

让客户端使用循环

boolean quit = false;
while (!quit) {
    sentence = this.inUser.readLine();
    quit = sentence.trim().equals("quit");
    this.out.writeBytes(sentence + '\n');
    modifiedSentence = this.inServeur.readLine();
    System.out.println("FROM SERVER: " + modifiedSentence);
}
this.socket.close();

服务器看起来不错，但是当我有多个客户端时，它会区分多个客户端？我怎么播出？发送给焦点客户的消息？

是的，此服务器阻止读取第一个客户端，因此任何其他客户端都必须等待。您可能希望在单独的线程中将阻塞代码放在每个客户端上，或者将其提交给ExecutiveService。并且所有特定于客户端的变量都不能在单个服务器类中，因为每个客户端都需要一个集合。

while (true) {
    final Socket socket = serverSocket.accept();
    new Thread(() -> {
        try {
            BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            DataOutputStream out = new DataOutputStream(socket.getOutputStream());
            boolean quit = false;
            while (!quit) {
                String msgClient = in.readLine();
                quit = msgClient.trim().equals("quit");
                System.out.println("Received: " + msgClient);
                String msgServeur = msgClient.toUpperCase() + '\n';
                out.writeBytes(msgServeur);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }).start();
}

Java - 客户端和服务器通信问题

1 个答案: