如何用一台服務器做多個客戶端？

Question

這是我的服務器。 我正在使用JFrame。 實際上，當我在pc 1中運行服務器時，我有很多pc，然后在pc 2和pc 3上運行客戶端。pc 3客戶端連接但服務器無法接收到消息。 當PC 2客戶端已連接時。

 package server;
 import java.net.*;
 import java.io.*;

public class FrmServer extends javax.swing.JFrame {

ServerSocket providerSocket;
Socket connection=null;
ObjectOutputStream out;
ObjectInputStream in;
String message;

//To run the connection
public void run(){

用於連接

    try{
        providerSocket = new ServerSocket(9090);
        msgArea.append("Waiting for connection....");
        connection = providerSocket.accept();

        out = new ObjectOutputStream(connection.getOutputStream());
        out.flush();

        in = new ObjectInputStream(connection.getInputStream());
        sendmessage("Connection is successful...");

        while(true){
           message = (String)in.readObject();

           if(!message.isEmpty())
               msgArea.append("\nClient: "+message);
        }

    }
    catch(Exception e){

    }

}

public void sendmessage(String msg){

    try{
        out.writeObject(msg);
        out.flush();
        msgArea.append("\nServer: "+msg);
    }catch(Exception e){

    }
}

/**
 * Creates new form FrmServer
 */
public FrmServer() {
    initComponents();
}

private void btnSendActionPerformed(java.awt.event.ActionEvent evt) {                                        
    // TODO add your handling code here:
    sendmessage(txt.getText());
} 
public static void main(String args[]) {
FrmServer s = new FrmServer();
    s.setVisible(true);
    s.run();

}

客戶

package client;

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

public class FrmClient extends javax.swing.JFrame {

Socket requestSocket;
ObjectInputStream in;
ObjectOutputStream out;
String message;
/**
 * Creates new form FrmClient
 */
public FrmClient() {
    initComponents();
}

public void run(){

    try{
        requestSocket = new Socket("10.99.225.12",9090);
        msgArea.append("Connected to the server...");

        out = new ObjectOutputStream(requestSocket.getOutputStream());
        out.flush();

        in = new ObjectInputStream(requestSocket.getInputStream());

        while(true){
           message = (String)in.readObject(); 

           if(!message.isEmpty());
               msgArea.append("\nServer: "+message);
        }
    }
    catch(Exception e){

    }

}

public void sendmessage(String msg){

    try{
        out.writeObject(msg);
        out.flush();

        msgArea.append("\nClient: "+msg);
    }
    catch(Exception e){

    }

}

private void btnSendActionPerformed(java.awt.event.ActionEvent evt) {                                        
    // TODO add your handling code here:
    sendmessage(txt.getText());
}  
private void formWindowClosing(java.awt.event.WindowEvent evt) {                                   
    // TODO add your handling code here:

    try{
        sendmessage("Got to go.. Goodbye!");
        in.close();
        out.close();
        requestSocket.close();
    }
    catch(Exception e){

    }

} 
public static void main(String args[]) {
FrmClient c = new FrmClient();
    c.setVisible(true);
    c.run();
}

Answer 1

您必須為每個套接字（客戶端）創建一個線程，並對其進行處理。

到目前為止，我只看到一個連接，因為您只初始化了一次connection 。

您可以列出所有套接字，並對其輸入/輸出流進行讀寫操作。

Answer 2

您需要一個專用線程來連續監聽連接。

接受連接后，為每個接受的連接創建兩個線程，一個用於讀取傳入的數據，另一個用於將數據寫入套接字。

盡管可以用更好的方式編寫代碼，但這是對代碼的簡單修改。

1. 使您的JFrame類實現Runnable。

    public class FrmServer extends javax.swing.JFrame implements Runnable 

2. 在您的JFrame類中實現run方法

    @Override public void run() { while (true) { try { msgArea.append("Waiting for connection...."); connection = providerSocket.accept(); new ConnectionWriter(connection, msgArea).start(); new ConnectionReader(connection, msgArea).start(); } catch (IOException ex) { System.err.out(ex); } } } 

3. 創建一個線程以寫入套接字

    public class ConnectionWriter extends Thread { ObjectOutputStream out; Socket connection; JTextArea msgArea; public ConnectionWriter(Socket connection, JTextArea msgArea) { this.connection = connection; this.msgArea = msgArea; } @Override public void run() { try { out = new ObjectOutputStream(connection.getOutputStream()); out.flush(); sendmessage("Connection is successful..."); } catch (IOException e) { System.out.println(e); } } public void sendmessage(String msg) { try { out.writeObject(msg); out.flush(); msgArea.append("\\nServer: " + msg); } catch (IOException e) { System.err.println(e); } } } 

4. 創建一個線程以從套接字讀取。

    public class ConnectionReader extends Thread { ObjectInputStream in; Socket connection; JTextArea msgArea; public ConnectionReader(Socket connection, JTextArea msgArea) { this.connection = connection; this.msgArea = msgArea; } @Override public void run() { try { in = new ObjectInputStream(connection.getInputStream()); while (true) { String message = (String) in.readObject(); if (!message.isEmpty()) { msgArea.append("\\nClient: " + message); } } } catch (IOException ex) { System.err.out(e); } } }