I need to limit the number of client that can connect to the server . I only want 3 clients that can connect not more.
I tried if else conditions. and some loops.
public class server {
ServerSocket ss;
boolean quite=false;
ArrayList<MultiServerConnection> OurDomainsConnections=new ArrayList<MultiServerConnection>();
public static void main(String[] args) {
new server();
}
public server() {
try {
//TODO use method to take this as an input from user)
ss=new ServerSocket(3333);//here we are using connection 3333 (change as you want
while(!quite)
{
Socket s=ss.accept();//when a connection to the domain is found we accept it
MultiServerConnection OurConnection = new MultiServerConnection(s,this);
OurConnection.start();//Start Thread
OurDomainsConnections.add(OurConnection);//add connection to our Domain Connection
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}//make sure its bloody same with client it took my 15 min to realize that XD
}
}
public class MultiServerConnection extends Thread {
Socket s;
DataInputStream din;
DataOutputStream dout;
server ss;
boolean quite=false;
public MultiServerConnection(Socket OurSocket,server OurServer)
{
super("MultiServerConnection");//server connection thread
this.s=OurSocket;
this.ss=OurServer;
}
public void ServerOutClientIn(String OutText)
{
try {
long ThreadID=this.getId();
dout.writeUTF(OutText);
dout.flush();//this is because of a buffer error :<
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void ServerOutAllClientIn(String OutText)
{
for(int i=0;i<ss.OurDomainsConnections.size();i++)
{
MultiServerConnection Connection=ss.OurDomainsConnections.get(i);
Connection.ServerOutClientIn(OutText);
}
}
public void run()
{
try {
din=new DataInputStream(s.getInputStream());
dout=new DataOutputStream(s.getOutputStream());
while(!quite)
{
while(din.available()==0)
{
try {
Thread.sleep(1);//sleep if there is not data coming
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
String ComingText=din.readUTF();
ServerOutAllClientIn(ComingText);
}
din.close();
dout.close();
s.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
public class MultiClients extends Thread {
Socket s;
DataInputStream din;
DataOutputStream dout;
boolean quite=false;
public ClientData c;
public interface1 GUI;
public MultiClients(Socket OurMultiSocket, interface1 gui)
{
s=OurMultiSocket;
c=new ClientData();
GUI=gui;
}
public void ClientOutServerIn(String Text)
{
//write the line from console to server
try {
if(Text.equals("change channel"))
{
System.out.print("sending changing channel: "+Text+"\n");
dout.writeUTF(Text);
dout.flush();
}
else if(Text.equals("new user"))
{
System.out.print("sending new user: "+ Text+"\n");
dout.writeUTF(Text+":"+c.GetName()+"="+c.GetChannel());
dout.flush();
}
else
{
dout.writeUTF(c.GetChannel()+"="+this.getName()+": "+Text);
dout.flush();
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void SetClient(String channel,String Name)
{
c.SetName(Name);
c.SetChannel(channel);
}
public void run()
{
try {
din=new DataInputStream(s.getInputStream());
dout=new DataOutputStream(s.getOutputStream());
while(!quite)
{
try {
while(din.available()==0)
{
try {
Thread.sleep(1);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
//if there is something just show it on console
//and then go back and do the same
String reply=din.readUTF();
String Chan=ExtractChannel(reply);
String name=ExtractName(reply);
/*if (reply.equals("change channel"))
{
System.out.print("changing channel in body: "+reply+"\n");
//GUI.ClearDisplay();
setChangedChannel();
}*/
if(name.equals("new user"))
{
System.out.print("new user in body: "+reply+"\n");
//GUI.ClearDisplay();
setChannel(reply);
}
else
{
PrintReply(Chan,reply);
}
//System.out.println(reply);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
try {
din.close();
dout.close();
s.close();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
}
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
try {
din.close();
dout.close();
s.close();
} catch (IOException x) {
// TODO Auto-generated catch block
x.printStackTrace();
}
}
}
public void CloseClient()
{
try {
din.close();
dout.close();
s.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public String ExtractName(String x)
{
String[]Y=x.split(":");
return Y[0];
}
public String ExtractChannel(String X)
{
String[]Y=X.split("=");
return Y[0];
}
public void PrintReply(String Chan,String Rep)
{
if(c.GetChannel().equals(Chan))
{
String []Y=Rep.split("=");
GUI.setDisplay(Y[1]);
//System.out.println(Y[1]+"\n \n \n \n");
}
}
public void setChannel(String x)
{
String []Y=x.split(":");
String []Z=Y[1].split("=");
System.out.print("setting "+Z[0]+" channel to "+Z[1]+"\n");
GUI.setUserInChannel(Z[0]);
}
public void setChangedChannel()
{
GUI.setUserInChannel(c.GetName()+": "+c.GetChannel());
}
class ClientData
{
public String ClientName;
public String channel;
public void SetChannel(String Chan)
{
channel=Chan;
}
public void SetName(String name)
{
ClientName=name;
}
public String GetChannel()
{
return channel;
}
public String GetName()
{
return ClientName;
}
}
}
in this code. more than 5 user can can chat together. i only want to allow 3 user to connect and to chat.
You can use AtomicInteger as a counter to check how many clients you have already connected:
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.ArrayList;
import java.util.concurrent.atomic.AtomicInteger;
public class server {
ServerSocket ss;
boolean quite=false;
ArrayList<MultiServerConnection> OurDomainsConnections=new ArrayList<MultiServerConnection>();
final AtomicInteger runningCount = new AtomicInteger(0);
final Integer limit = 3;
public static void main(String[] args) {
new server();
}
public server() {
try {
//TODO use method to take this as an input from user)
ss=new ServerSocket(3333);//here we are using connection 3333 (change as you want
while(!quite)
{
Socket s=ss.accept();//when a connection to the domain is found we accept it
if (runningCount.incrementAndGet() < limit){ //increment number of clients and check
MultiServerConnection OurConnection = new MultiServerConnection(s,this, runningCount::decrementAndGet);
OurConnection.start();//Start Thread
OurDomainsConnections.add(OurConnection);//add connection to our Domain Connection
} else {
runningCount.decrementAndGet();
s.close();
System.out.println("limit exceeded");
}
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}//make sure its bloody same with client it took my 15 min to realize that XD
}
}
interface Callback {
void call();
}
class MultiServerConnection extends Thread {
Socket s;
DataInputStream din;
DataOutputStream dout;
server ss;
boolean quite=false;
final Callback callbackOnFinish;
public MultiServerConnection(Socket OurSocket,server OurServer, Callback callbackOnFinish)
{
super("MultiServerConnection");//server connection thread
this.s=OurSocket;
this.ss=OurServer;
this.callbackOnFinish = callbackOnFinish;
}
public void ServerOutClientIn(String OutText)
{
try {
long ThreadID=this.getId();
dout.writeUTF(OutText);
dout.flush();//this is because of a buffer error :<
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void ServerOutAllClientIn(String OutText)
{
for(int i=0;i<ss.OurDomainsConnections.size();i++)
{
MultiServerConnection Connection=ss.OurDomainsConnections.get(i);
Connection.ServerOutClientIn(OutText);
}
}
public void run()
{
try {
din=new DataInputStream(s.getInputStream());
dout=new DataOutputStream(s.getOutputStream());
while(!quite)
{
while(din.available()==0)
{
try {
Thread.sleep(1);//sleep if there is not data coming
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
String ComingText=din.readUTF();
ServerOutAllClientIn(ComingText);
}
din.close();
dout.close();
s.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
callbackOnFinish.call();
}
}
}
When a new connection is accepted runningCount is atomically increased and value is got by runningCount.incrementAndGet(). Then if value below the limit - new MultiServerConnection is created with a callback. The callback is used for decrementing a counter on exit. If counter equal or above the limit => socket will be closed and error message printed. It is good to have a message passed to the socket.
P.S. I have not reviewed your solution. I've just added the feture you requested.