hello i've just created a server that accepts several clients inside a while loop but i want to accept only a determinated number of clients that ipass in the command-line arguments too for example:

java ServerEx -max_num_clients 3 -port 1982


how can i make to the server don't allow a fourth client for this example?

this is the code many thanks

			

			

			import java.io.BufferedReader;
			

			import java.io.InputStream;
			

			import java.io.InputStreamReader;
			

			import java.io.OutputStream;
			

			import java.io.PrintWriter;
			

			import java.io.IOException;
			

			import java.net.Socket;
			

			import java.net.ServerSocket;
			

			import java.net.SocketException;
			

			import java.util.LinkedList;
			

			import java.util.ListIterator;
			

			

			public class ServerEx
			

			{
			

			

			private LinkedList    reg_thread = null;
			

			private ServerSocket  socketServer = null;
			

			private Socket        socketClient = null;
			

			

			/*_____________________________________________________________________________
			

			*
			

			*
			

			*                      M         A         I          N
			

			*
			

			*___________________________________________________________________________*/
			

			

			public static void main (String argv [ ]) throws IOException
			

			{
			

			int  Port = 0,
			

			count = 0,
			

			maxThreads = 0,
			

			i = 0,
			

			j = 0;
			

			ServerEx      server = null;
			

			SocketThread  conn = null;
			

			boolean listening_connection = true;
			

			

			server = new ServerEx ();
			

			

			/*---command line arguments---*/
			

			

			if( argv.length != 4 )
			

			{
			

			System.err.println( "usage: java ServerEx -port
			<#> " +
			

			"-max_num_clients
			<#>" );
			

			System.exit ( 0 );
			

			}
			

			else
			

			for ( i = 0; i
			< argv.length; i++ )
			

			{
			

			if ( argv [ i ].compareTo ( "-port" ) == 0 )
			

			{
			

			try
			

			{
			

			Port = Integer.parseInt ( argv [ i+1 ] );
			

			}
			

			catch( NumberFormatException e)
			

			{
			

			System.err.println ("
			

			The port must be a number:  "+
			

			e.toString ());
			

			System.err.println( "usage: java ServerEx -port
			<#> " +
			

			"-max_num_clients
			<#>" );
			

			

			System.exit ( 0 );
			

			}
			

			}
			

			else if ( argv [ i ].compareTo ( "-max_num_clients" ) == 0 )
			

			{
			

			try
			

			{
			

			maxThreads = Integer.parseInt ( argv [ i+1 ] );
			

			}
			

			catch ( NumberFormatException e )
			

			{
			

			System.err.println ( "
			

			This field must be in number:   "+
			

			e.toString ());
			

			

			System.err.println( "usage: java ServerEx -port
			<#> " +
			

			"-max_num_clients
			<#>" );
			

			System.exit ( 0 );
			

			}
			

			}
			

			}
			

			

			for ( i = 0; i
			< 4; i += 2)
			

			{
			

			if ( argv[ i ].compareTo ( "-port" )            != 0 &&
			

			argv[ i ].compareTo ( "-max_num_clients" ) != 0 )
			

			{
			

			System.err.println ("
			

			

			invalid option: '" + argv [ i ] + "'
			

			" +
			

			"usage: java ServerEx -port
			<# > " +
			

			"-max_num_clients
			<#> ");
			

			System.exit ( 0 );
			

			}
			

			}
			

			for (i = 2; i >= 0; i-= 2)
			

			{
			

			for (j = 0; j
			<= i-1; j += 2)
			

			if ( argv [ i ].compareTo (argv [ j ]) == 0)
			

			{
			

			System.err.println ("
			

			

			duplicated option: '" +
			

			argv [ i ]+"'
			

			" +
			

			"usage: java ServerEx -port
			<# > " +
			

			"-max_num_clients
			<#> ");
			

			System.exit ( 0 );
			

			}
			

			}
			

			

			if ( Port
			< 1 || Port > 65535 )
			

			{
			

			

			System.err.println( "
			

			port must be between 1 and 65535
			

			

			" +
			

			"usage: java ServerEx -port
			<#> " +
			

			"-max_num_clients
			<#> ");
			

			System.exit ( 0 );
			

			

			}
			

			else if (maxThreads
			< 0 )
			

			{
			

			System.err.println ("
			

			max connections must be in positive
			

			

			" +
			

			"usage: java ServerEx -port
			<#> " +
			

			"-max_num_clients
			<#> ");
			

			System.exit ( 0 );
			

			}
			

			

			try
			

			{
			

			server.socketServer = new ServerSocket( Port );
			

			}
			

			catch (IOException e)
			

			

			{
			

			System.err.println("could not listen on that port " + e.toString());
			

			System.exit (0);
			

			}
			

			

			

			System.out.println("Server created. Waiting client connections...");
			

			System.out.println("only " + maxThreads + " connections will be allowed " +
			

			"at the same time");
			

			

			server.new_list();
			

			

			

			

			

			

			//SHOULD I CHANGE THIS FOR A "FOR LOOP???"
			

			while ( listening_connection )
			

			{
			

			try
			

			{
			

			server.socketClient = server.socketServer.accept();
			

			

			conn  = new SocketThread (server.socketClient,
			

			count, server);
			

			conn.thisReference( conn );
			

			

			conn.start();
			

			

			System.out.println("
			

			

			client: " + count + " accepted " );
			

			count++;
			

			server.reg_thread.addLast ( conn );
			

			

			

			

			

			/*-----THIS DONT WORK----------------*/
			

			if ( server.reg_thread.size() > maxThreads )
			

			{
			

			System.err.println ("server is busy");
			

			listening_connection = false;
			

			}
			

			

			}
			

			catch (SocketException e)
			

			{
			

			System.err.println ("the server has been closed" );
			

			listening_connection = false;
			

			}
			

			}
			

			}/*____________________________ END MAIN __________________________________*/
			

			

			

			

			/*_________________________________Shutdown__________________________________*/
			

			public void Shutdown (SocketThread this_socket)
			

			{
			

			ListIterator ite = reg_thread.listIterator(0);
			

			SocketThread   conn = null;
			

			

			while ( ite.hasNext ())
			

			{
			

			conn  = (SocketThread) ite.next ();
			

			

			

			if( conn != this_socket )
			

			{
			

			conn.Broadcast();
			

			conn.Stop();
			

			}
			

			

			}
			

			

			}/*_____________________________end Shutdown_______________________________*/
			

			

			

			/*_________________________________new_list__________________________________*/
			

			public void new_list()
			

			{
			

			reg_thread = new LinkedList();
			

			}/*____________________________end new_list________________________________*/
			

			

			

			/*________________________________Interrupt__________________________________*/
			

			public void Interrupt() throws IOException
			

			{
			

			socketServer.close();
			

			

			}/*___________________________end Interrupt________________________________*/
			

			

			}/*_________________________ END ServerEx class______________________________*/
			

			

			/*===========================================================================*/