Java聊天系统

Question

我在广播每个客户端发送的消息时遇到问题。服务器可以从多个客户端接收每条消息，但不能广播它。错误消息表示连接被拒绝 客户端：

    public void initializeConnection(){
    try {
        host = InetAddress.getLocalHost();
        try{
              // Create file 
              FileWriter fstream = new FileWriter("src/out.txt", true);
              BufferedWriter out = new BufferedWriter(fstream);
              out.write(host.getHostAddress()+'\n');
              //Close the output stream
              out.close();
          }catch (Exception e){//Catch exception if any
              System.err.println("Error: " + e.getMessage());
          }
        clientSocket = new Socket(host.getHostAddress(), port);
        outToServer = new PrintWriter(clientSocket.getOutputStream(), true);
        inFromServer = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));

    }
    catch(IOException ioEx) {
        ioEx.printStackTrace();
    } 
}

public void actionPerformed(ActionEvent e)
{
    if(e.getSource()==quit){
        try {
            outToServer.close();
            clientSocket.close();
            System.exit(1);
        } catch (IOException e1) {
            e1.printStackTrace();
        }
    }
    else if(e.getSource()==button){ 
        if(outMsgArea.getText()!=null || !outMsgArea.getText().equals("")){
            String message = outMsgArea.getText();
            outToServer.println(clientName+": "+message);
            outMsgArea.setText("");
        }
    }
}

public void run(){
    try {
        while(true){
            String message = inFromServer.readLine();
            System.out.println(message);
                inMsgArea.append(message+'\n');
        }
    } catch (IOException e) {
        e.printStackTrace();
    }
}

服务器：

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

public class RelayChatServer {
public static int port = 44442;
ServerSocket server;
public void listenSocket(){
  try{
    server = new ServerSocket(port);
  } catch (IOException e) {
    System.out.println("Could not listen on port 4444");
    System.exit(-1);
  }
  while(true){
    ClientWorker w;
    try{
//server.accept returns a client connection
      w = new ClientWorker(server.accept());
      Thread t = new Thread(w);
      t.start();
    } catch (IOException e) {
      System.out.println("Accept failed: 4444");
      System.exit(-1);
    }
  }
}

protected void finalize(){
    //Objects created in run method are finalized when
    //program terminates and thread exits
         try{
            server.close();
        } catch (IOException e) {
            System.out.println("Could not close socket");
            System.exit(-1);
        }
      }

public static void main(String[] args) {
    new RelayChatServer().listenSocket();
}

}

class ClientWorker implements Runnable {
  private Socket client;

//Constructor
  ClientWorker(Socket client) {
    this.client = client;
  }

  public void run(){
    String line;
BufferedReader in = null;
PrintWriter out = null;
try{
  in = new BufferedReader(new 
    InputStreamReader(client.getInputStream()));
  //out = new 
  //  PrintWriter(client.getOutputStream(), true);
} catch (IOException e) {
  System.out.println("in or out failed");
  System.exit(-1);
}

while(true){
  try{
    line = in.readLine();
//Send data back to client
    //out.println(line);
//Append data to text area
    if(line!=null && line!=""){
        System.out.println(line);
    try{
          // Open the file that is the first 
          // command line parameter
          FileInputStream fstream = new FileInputStream("out.txt");
          BufferedReader br = new BufferedReader(new InputStreamReader(fstream));
          String strLine;
          //Read File Line By Line
          Socket s;
          PrintWriter prnt;
          while ((strLine = br.readLine()) != null && (strLine = br.readLine()) != "")   {
          // Print the content on the console
              s = new Socket(strLine, 44441);
              prnt = new PrintWriter(s.getOutputStream(),true);
              prnt.println(line);
              System.out.println(strLine);
              prnt.close();
              s.close();
          }
          //Close the input stream
          //inp.close();
            }catch (Exception e){//Catch exception if any
          System.err.println("Error: " + e.getMessage());
          }
    }
   }catch (IOException e) {
    System.out.println("Read failed");
    e.printStackTrace();
    System.exit(-1);
   }
}
  }

}

---

Exception开始：

java.net.ConnectException: Connection refused: connect

扩展输出如下：

Answer 1

我有点困惑为什么你试图打开一个新的套接字（你打算将它发送回客户端吗？）基于你从文件中读取的字符串。也许

s = new Socket(strLine, 44441);
prnt = new PrintWriter(s.getOutputStream(),true);

应该是：

prnt = new PrintWriter(client.getOutputStream(),true);

目前我没有看到你向客户发回任何东西。

编辑：确定尝试以下内容：

static final ArrayList<ClientWorker> connectedClients = new ArrayList<ClientWorker>();
class ClientWorker implements Runnable {

    private Socket socket;
    private PrintWriter writer;

    ClientWorker(Socket socket) {
        this.socket = socket;
        try {
            this.writer = new PrintWriter(socket.getOutputStream(), true);
        } catch (IOException ex) { /* do something sensible */ }
    }

    public void run() {
        synchronized(connectedClients) {
            connectedClients.add(this);
        }

        BufferedReader in = null;
        try {
            in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
        } catch (IOException e) { /* do something sensible */ }

        while (true) {
            try {
                String line = in.readLine();
                if (line != null && line != "") {
                    synchronized (connectedClients) {
                        for (int i = 0; i < connectedClients.size(); ++i){
                            ClientWorker client = connectedClients.get(i);
                            client.writer.println(line);
                        }
                    }
                }
            } catch (IOException e) { /* do something sensible */ }
        }
    }
}