不同类之间的函数调用

Question

I have three separate classes that are login.java, LiveMonitoring.java, and HandleMultipleClients.java. Following is the code of all respective classes

Login.java

 try
            {
                serverSock = new ServerSocket(2101);
                while (true) 
                {
                    sock = serverSock.accept();
                    HandleMultipleClients hmc=new HandleMultipleClients();
                    hmc.Connect(sock); 
                }

HandleMultipleClients.java

public class HandleMultipleClients
{
    Map<Integer, java.net.Socket> clients = new HashMap<Integer, java.net.Socket> ();
    Socket soc;
    ServerSocket serverSock;
    DataOutputStream dos;
    DataInputStream dis;
    public HandleMultipleClients()
    {

    }
    public void Connect(Socket sock)
    {
        soc=sock;
        clients.put(soc.getPort(), soc);
    }
    public void messagetospecificclients(String ipaddress,String choice) throws IOException, InterruptedException
    {
        System.out.print(ipaddress+"\n"+choice);
        for (Iterator<Integer> iter = clients.keySet().iterator(); iter.hasNext(); )
        {
            System.out.print("ok1");
            int key = iter.next();
            java.net.Socket client = clients.get(key);
            InetAddress zee = client.getInetAddress();
            String s = zee.getHostAddress();
            System.out.print(s);
            if (zee.getHostAddress().equals(ipaddress))
            {
                System.out.print("ok2");
                dos =new DataOutputStream(client.getOutputStream());
                dos.writeUTF(choice);
            }

LiveMonitoring.java

HandleMultipleClients hmc=new HandleMultipleClients();
        try
        {
            hmc.messagetospecificclients("192.168.1.102","apps");
        }

Now the problem is when i call hmc.messagetospecificclients("192.168.1.102","apps"); it goes to the HandleMultipleClients class and just print the IPaddress and apps but it is not going through the for loop.Kindly tell me what i am doing wrong.

Answer 1

You're creating an instance of the object and adding a "client" to it here:

HandleMultipleClients hmc=new HandleMultipleClients();
hmc.Connect(sock);

But you never call messagetospecificclients() on that instance.

Then you create another instance and call that method here:

HandleMultipleClients hmc=new HandleMultipleClients();
try
{
    hmc.messagetospecificclients("192.168.1.102","apps");
}

But you never called Connect() on that instance to add clients to it.

(As an analogy... Imagine that you have two identical cars. Same make, same model, came off the same production line. You have put gas in one of those cars. And you're trying to drive the other one. But you can't, because it doesn't have gas in it.)

Call messagetospecificclients() on the instance which has the values that have been set:

HandleMultipleClients hmc=new HandleMultipleClients();
hmc.Connect(sock);
try
{
    hmc.messagetospecificclients("192.168.1.102","apps");
}