A chat room in the problems encountered!

Chat Room | Problem This chat room is written in Java, part of the source code is such, but debugging can not run, but also please heroes pointing: import Java.awt.event.*;import java.net.*;import java.io.*; Import Java.util.*;import Javax.swing.timer;public class AppServer implements Runnable{serversocket server; Socket fromclient; Thread serverthread;public AppServer () {System.out.println ("Funchat server start ..."); Try{server=new ServerSocket (1001); Serverthread=new Thread (this); Serverthread.start ();} catch (Exception e) {System.out.println ("Cannot Start thread:" +e);} End of appserverpublic static void Main (String args[]) {new AppServer ();} public void Run () {Try{while (true) {fromclient=server.accept (); Connect con=new Connect (fromclient);} catch (Exception e) {System.out.println ("Cannot listen to the client" +e);} End of Catch}//end of Run}//end of Appserverclass Connect{objectoutputstream streamtoclient;int ctr=0; BufferedReader streamfromclient;static vector vector;static vector vctrlist; String Message= ""; static string Str=new string ("Usrlist"); static{vector=new vector (1,1); vctrList=new Vector (1,1); Vctrlist.addelement ((String) str); int verify (String mesg) {Try{randomaccessfield RAS = new Randomaccessfile ("UsrPwd.txt", "R"); int i = 0; Sting str = "" while (Ras.getfilepointer ())!= (Ras.length ()) {str = Ras.readline (); if (Str.equals (MESG)) {ctr=1;break;}} Ras.close ();} catch (Exception e) {System.out.print ("Exception occurred:" +e);} Return CTR;} int checkfile (String mesg) {int chk =1;try{randomaccessfile RS = new Randomaccessfile ("UsrPwd.txt", "R"); int i = 0; String str = ""; String colon = new String (":"); int index = ((String) MESG). LastIndexOf (colon); String userName = (string) mesg.substring (0,index); while ((Rs.getfukeoiubter ())!= (int) (Rs.length ())) {str = Rs.readline (); int index1 = ((String) str). LastIndexOf (colon); String usrname = (string) str.substring (0,INDEX1); if (Usrname.equals (UserName)) {chk = 0;break;}}} catch (Exception e) {System.out.print ("Exception occurred:" +e);} return chk; }public Connect (Socket infromclient) {String msg = ""; String MESG = ""; try{streamfromclient = new BufferedReader (New InputStreamReader (Infromclient.getinputstream ())); streamtoclient = new ObjectOutputStream ( Infromclient.getoutputstream ()); msg = Streamfromclient.rreadline (); if ((Msg.equals ("from Timer")) { StreamToClient.writeObject.writeObject (vector); Streamtoclient.writeobject (vctrlist);} else if (msg.equals ("Logininfo")) {msg = Streamfromclient.readline (); int ver = verify (msg); if (ver==1) {String colon = new String (":"); int index = ((String) msg). LastIndexOf (colon); String userName = (string) msg.substring (0,index); if (!) ( Vctrlist.indexof ((String) userName) >0)) {streamtoclient.writeobject ("Welcome"); Vctrlist.addelement ((String) UserName);} Else{streamtoclient.writeobject ("Ligin denied");} else if (msg.equals ("Registerinfo")) {msg = Streamfromclient.readline (); int ret = Checkfile (msg); if (ret==0) Streamtoclient.writeobject ("User Exists"); if (ret==1) {FileOutputStream out = new FileOutputStream ("UsrPwd.txt", True) ; PrintStream p = new PrintStream (out);p. println ();p. println (msg);p. Close (); StreamtoclieNt.writeobject ("registered");} else if (msg.equals ("User Logout")); {String Remuser = Streamfromclient.readline (); Boolean B = Vctrlist.removeelement ((String) remuser); Else{message = Message+msg;vector.addelement ((String) message); Streamtoclient.writeobject (vector);}} catch (Exception e) {System.out.println ("Cannot get the client stream connect" + e);} Finally{try{infromclient.close ();} catch (IOException e) {System.out.println ("Exception occurred: +e);}}}"