Can any one help me with this chat server

Question

The code below is of a client and server but the problem is that the msg can be sent only from the server and not the client I want that whenever a msg is sent from the server the control for writing the msg should go on to the client n den vise versa n should continue till the connection is terminated..plz help me....!
CoDES
for client
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.InetAddress;
import java.net.Socket;
import java.net.UnknownHostException;
class client {
public static void main(String[] args) throws IOException {
Socket s =null;
BufferedReader b=null;
try{
s=new Socket( InetAddress.getLocalHost(),98);
b=new BufferedReader(new InputStreamReader(s.getInputStream()));
catch(UnknownHostException u) {
System.err.println("i dont know host");
System.exit(0);
String inp;
while((inp=b.readLine())!=null){
System.out.println(inp);
b.close();
s.close();
FOR SERVER$
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.nio.channels.ServerSocketChannel;
public class server {
public static void main(String[] args) throws IOException {
ServerSocket s1=null;
try{
s1=new ServerSocket(98);
}catch(IOException u1)
System.err.println("could not find port 98");
System.exit(1);
Socket c=null;
try{
c=s1.accept();
System.out.println("connection from"+c);
catch(IOException e)
System.out.println("accept failed");
System.exit(1);
PrintWriter out=new PrintWriter(c.getOutputStream(),true);
BufferedReader in=new BufferedReader(new InputStreamReader(c.getInputStream()));
String I;
BufferedReader sin=new BufferedReader(new InputStreamReader(System.in));
System.out.println("i am ready to type now");
while((I=sin.readLine())!=null) {
out.println(I);
out.close();
sin.close();
c.close();
s1.close();
}

Answer 1

What you need is to have two loops running at the same time. One for receiving messages and other for waiting user input. This can be done by using separate threads.
For example after client has made connection to server, start a new thread that runs loop for receiving messages from the socket and printing them to System.out. Then in the default thread start loop for reading users input. The server could have similar structure.
So, what I think you are looking for are threads.