import java.io.*;
import java.net.*;
import java.util.*;
public class MyServer{
ServerSocket ss;
Socket s;
ArrayList al=new ArrayList();
ArrayList al1=new ArrayList();
ArrayList al2=new ArrayList();
ArrayList alname=new ArrayList();
Socket s1,s2;
MyServer()throws IOException{
ss=new ServerSocket(1004); // create server socket
while(true){
s=ss.accept(); //accept the client socket
s1=ss.accept();
s2=ss.accept();
al.add(s); // add the client socket in arraylist
al1.add(s1);
al2.add(s2);
System.out.println("Client is Connected");
MyThread2 m=new MyThread2(s2,al2,alname); //new thread for maintaning the list of user name
Thread t2=new Thread(m);
t2.start();
MyThread r=new MyThread(s,al);//new thread for receive and sending the messages
Thread t=new Thread(r);
t.start();
MyThread1 my=new MyThread1(s1,al1,s,s2); // new thread for update the list of user name
Thread t1=new Thread(my);
t1.start();
}
}
public static void main(String[] args){
try{
new MyServer();
}catch (IOException e){}
}
}
//class is used to update the list of user name
class MyThread1 implements Runnable{
Socket s1,s,s2;
static ArrayList al1;
DataInputStream ddin;
String sname;
MyThread1(Socket s1,ArrayList al1,Socket s,Socket s2){
this.s1=s1;
this.al1=al1;
this.s=s;
this.s2=s2;
}
public void run(){
try{
ddin=new DataInputStream(s1.getInputStream());
while(true){
sname=ddin.readUTF();
System.out.println("Exit :"+sname);
MyThread2.alname.remove(sname);//remove the logout user name from arraylist
MyThread2.every();
al1.remove(s1);
MyThread.al.remove(s);
MyThread2.al2.remove(s2);
if(al1.isEmpty())
System.exit(0); //all client has been logout
}
}catch(Exception ie){}
}
}
// class is used to maintain the list of all online users
class MyThread2 implements Runnable{
Socket s2;
static ArrayList al2;
static ArrayList alname;
static DataInputStream din1;
static DataOutputStream dout1;
MyThread2(Socket s2,ArrayList al2,ArrayList alname){
this.s2=s2;
this.al2=al2;
this.alname=alname;
}
public void run(){
try{
din1= new DataInputStream(s2.getInputStream());
alname.add(din1.readUTF()); // store the user name in arraylist
every();
}catch(Exception oe){System.out.println("Main expression"+oe);}
}
// send the list of user name to all client
static void every()throws Exception{
Iterator i1=al2.iterator();
Socket st1;
while(i1.hasNext()){
st1=(Socket)i1.next();
dout1=new DataOutputStream(st1.getOutputStream());
ObjectOutputStream obj=new ObjectOutputStream(dout1);
obj.writeObject(alname); //write the list of users in stream of all clients
dout1.flush();
obj.flush();
}
}
}
//class is used to receive the message and send it to all clients
class MyThread implements Runnable{
Socket s;
static ArrayList al;
DataInputStream din;
DataOutputStream dout;
MyThread(Socket s, ArrayList al){
this.s=s;
this.al=al;
}
public void run(){
String str;
int i=1;
try{
din=new DataInputStream(s.getInputStream());
}catch(Exception e){}
while(i==1){
try{
str=din.readUTF(); //read the message
distribute(str);
}catch (IOException e){}
}
}
// send it to all clients
public void distribute(String str)throws IOException{
Iterator i=al.iterator();
Socket st;
while(i.hasNext()){
st=(Socket)i.next();
dout=new DataOutputStream(st.getOutputStream());
dout.writeUTF(str);
dout.flush();
}
}
}
I do't know what it means..
need serious help.
