java - 多线程服务器仅从一个客户端 JAVA 接收数据

Question

我已经创建了一个简单的多线程服务器。每次它接受客户端时，都会创建一个 DataInputStream 和 DataOutputStream 并开始通信

服务器:

public class Connection implements Runnable{
boolean isAlreadyOpened = false;

@Override
public void run() {
    // TODO Auto-generated method stub  
    try {           
        ServerSocket ss = new ServerSocket(7000);
        while(true){
            System.out.println("Il Server sta cercando Connessioni");
            Socket s = ss.accept();
            System.out.println("Il Server ha accettato un Client");

            Thread t2 = new Thread(new Runnable(){
                public void run(){             
                   try {

                        DataInputStream dis = new DataInputStream(s.getInputStream());
                        isAlreadyOpened = true;
                        DataOutputStream dos = new DataOutputStream(s.getOutputStream());
                        while(true){
                            String test = dis.readUTF();
                            dos.writeUTF(test);
                            System.out.println(test);
                            dos.flush();
                        }                       
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                        isAlreadyOpened = false;
                    }  
                }           
            });
            t2.start();
        }
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
 }  
}

我已经尝试连接一个 Android 应用程序和一个 JavaApp；每 40 秒这两个程序都会通过 writeUTF 发送一个字符串。两个客户端都正确建立了连接，但服务器只从最后一个连接到服务器的客户端接收数据。我怎样才能让服务器从/向所有客户端接收/发送数据？

编辑:

我试过这样设置:

public class Connection implements Runnable {

 @Override
  public void run() {

    try {
        ServerSocket ss = new ServerSocket(7000);
        while (true) {
            System.out.println("Server is listening");
            Socket s = ss.accept();
            System.out.println("Client Accepted");

            Thread t2 = new Thread(new Runnable() {
                public void run() {
                    try {
                        DataInputStream dis = new DataInputStream(s.getInputStream());
                        DataOutputStream dos = new DataOutputStream(s.getOutputStream());
                        while (true) {
                            String test = dis.readUTF();
                            dos.writeUTF(test);
                            System.out.println(test);
                            dos.flush();
                        }
                    } catch (IOException 
                        e.printStackTrace();
                    } finally {
                        try {
                            s.close();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                }
            });                 
    t2.start();
        }
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}

但是结果是一样的

编辑:

Andorid 客户端代码

public class Connection implements Runnable {
@Override
public void run() {
    try {
        Socket s = new Socket("127.0.0.1", 7000);
        DataInputStream dis = new DataInputStream(s.getInputStream());
        DataOutputStream dos = new DataOutputStream(s.getOutputStream());

        while(true){
           dos.writeUTF("FromAndroid");
            Log.d("InputStreammmm", dis.readUTF());
         Thread.sleep(10000)
        }

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

}

JAVA 应用客户端代码

@Override
public void run() {
     try {

        Socket socket = new Socket("127.0.0.1", 7000);
        System.out.println("Connessooo");
         DataInputStream dis = new DataInputStream(socket.getInputStream());
         DataOutputStream dos = new DataOutputStream(socket.getOutputStream());

         while(true){
         dos.writeUTF("Invioooooooooooooooooooooooooo");
         result = dis.readUTF();
         System.out.println(result);
         Thread.sleep(10000);
         }

    } catch (IOException e) {

        e.printStackTrace();
    } catch (InterruptedException e) {

        e.printStackTrace();
    }
}

使用套接字列表进行编辑:

public class Connection implements Runnable {
List<Socket> sList = new ArrayList<>();
Socket s;
int i = 0;

@Override
public void run() {
    // TODO Auto-generated method stub
    try {
        ServerSocket ss = new ServerSocket(7000);
        while (true) {
            System.out.println("Server Listening");
            s = ss.accept();
            sList.add(s);

            System.out.println("Accepted Client --- " +s.toString());
            Thread t2 = new Thread(new Runnable() {
                public void run() {
                    try {
                        DataInputStream dis = new DataInputStream(s.getInputStream());  

                        while (true) 
                        {
                            String test = dis.readUTF();
                            System.out.println("Message sent from -- " + sList.get(i).toString());
                            System.out.println(test);

                            while(i < sList.size()){
                                 DataOutputStream dos = new DataOutputStream(sList.get(i).getOutputStream());
                                 dos.writeUTF(test);    
                                 System.out.println("Message Sent to -- " + sList.get(i).toString());
                                 dos.flush();
                                 ++i;
                             }
                            i=0;
                        }
                    } catch (IOException e) 
                    {
                        e.printStackTrace();
                    } finally
                    {
                        try
                        {                      
                            System.out.println("Closing Socket --- " + sList.get(i).toString());
                            sList.get(i).close();
                            sList.remove(i);

                        }
                        catch (IOException e)
                        {
                            e.printStackTrace();
                        }
                    }
                }
            });
            t2.start();
        }
    } catch (IOException e) {
        e.printStackTrace();
    }

}

按照 EJP 的建议，以这种方式解决了我的问题...

Answer 1

无法复制。

测试程序，从您编辑的代码中复制粘贴并添加 final 到 Socket s 因为我使用的是 Java 7，并添加了客户端代码:

public class Connection implements Runnable
{

    @Override
    public void run()
    {

        try
        {
            ServerSocket ss = new ServerSocket(7000);
            while (true)
            {
                System.out.println("Server is listening");
                final Socket s = ss.accept();
                System.out.println("Client Accepted");

                Thread t2 = new Thread(new Runnable()
                {
                    public void run()
                    {
                        try
                        {
                            DataInputStream dis = new DataInputStream(s.getInputStream());
                            DataOutputStream dos = new DataOutputStream(s.getOutputStream());
                            while (true)
                            {
                                String test = dis.readUTF();
                                dos.writeUTF(test);
                                System.out.println(test);
                                dos.flush();
                            }
                        }
                        catch (IOException e)
                        {
                            e.printStackTrace();
                        }
                        finally
                        {
                            try
                            {
                                s.close();
                            }
                            catch (IOException e)
                            {
                                e.printStackTrace();
                            }
                        }
                    }
                });
                t2.start();
            }
        }
        catch (IOException e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }


    public static void main(String[] args) throws InterruptedException
    {
        Connection c = new Connection();
        Thread  t1 = new Thread(c);
        t1.setDaemon(true);
        t1.start();
        Runnable    r = new Runnable()
        {
            public void run()
            {
                try (Socket s = new Socket("localhost", 7000))
                {
                    DataOutputStream    dos = new DataOutputStream(s.getOutputStream());
                    DataInputStream dis = new DataInputStream(s.getInputStream());
                    for (int i = 0; i < 10; i++)
                    {
                        dos.writeUTF("Hello from "+Thread.currentThread().getName());
                        String  reply = dis.readUTF();
                        Thread.sleep(10*1000);
                    }
                }
                catch (IOException|InterruptedException exc)
                {
                    exc.printStackTrace();
                }
            }
        };
        Thread  t2 = new Thread(r);
        Thread  t3 = new Thread(r);
        t2.start();
        t3.start();
        t2.join();
        t3.join();
    }
}

输出:

Server is listening
Client Accepted
Server is listening
Client Accepted
Server is listening
Hello from Thread-1
Hello from Thread-2
Hello from Thread-2
Hello from Thread-1
Hello from Thread-2
Hello from Thread-1
Hello from Thread-2
Hello from Thread-1
Hello from Thread-1
Hello from Thread-2
Hello from Thread-1
Hello from Thread-2
Hello from Thread-2
Hello from Thread-1
Hello from Thread-1
Hello from Thread-2
Hello from Thread-2
Hello from Thread-1
Hello from Thread-2
Hello from Thread-1