How to display text on JTextField from another class?

import java.io.*; 
import java.net.*; 
import java.awt.*; 
import java.awt.event.*; 
import javax.swing.*;  

public class Client extends JFrame 
{ 	
    private JTextField enterField; 	
    private JTextArea displayArea; 	
    private ObjectOutputStream output; 	
    private ObjectInputStream input; 	
    private String message = ""; 	
    private String chatServer; 	
    private Socket client; 		 
	
public static void main(String[] args) 	
{ 		
     Client application; 			 		
      if(args.length == 0) 		
      application = new Client("127.0.0.1");
 	 		
     else 		
     application = new Client(args[0]); 	
        application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     application.runClient(); 	
} 	 	
public Client(String host)				
 { 		
          super("Client"); 		
          chatServer = host;						
//set server to which this client connects 		
Container container = getContentPane(); 		 		
enterField = new JTextField();			
//create enterField and register listener 		
enterField.setEnabled(false); 		
enterField.addActionListener(new ActionListener() 		
{ 			
public void actionPerformed(ActionEvent event)		
//send message to server 			
{ 				
sendData(event.getActionCommand()); 			
} 		
}); 														
// end call to addActionListener 					 		
container.add(enterField, BorderLayout.NORTH); 		
displayArea = new JTextArea(); 		
container.add(new JScrollPane(displayArea), BorderLayout.CENTER); 		
setSize(500, 350); 		
setVisible(true); 	} 	 	
public void runClient()							
//connect to server and process message from server 	
{	 		
try											
//connect to server, get streams, process connection 		
{ 			
connectToServer();			
//step 1 create socket to make connection 			

getStreams();				

//step 2 get input and output stream 			

processConnection();		

//step 3 process connection 			

closeConnection();			

//step 4 close connection 		

}								

//server close connection 		

catch(EOFException eofException) 		

{ 			

System.out.println("Server terminated connection"); 		

} 		

catch(IOException ioException)	 		

{ 			

ioException.printStackTrace(); 		

} 	

} 	 	


private void getStreams() throws 
IOException
						
//get stream to send and receive data 	
{ 		

output = new ObjectOutputStream(client.getOutputStream());
		
//set up output stream for objects
 		
output.flush();	
			 		
input = new ObjectInputStream(client.getInputStream());	
		
//set up input stream for objects
 		
displayArea.append("\nGot Input & Output Stream\n"); 
	
} 	 	

private void connectToServer() throws IOException	
				
//connect to server 
	
{ 
		
displayArea.setText("Attempting connection\n"); 
		
client = new Socket(InetAddress.getByName(chatServer), 8189);
		
//create socket to make connection to server 	
	
displayArea.append("Connect to: " + client.getInetAddress().getHostName());
		
//display connection information 	

} 	 	
private void processConnection() throws IOException	
	
//process connection with server 	

{	 		

enterField.setEnabled(true);	
					
//enable enterField so client user can send messages 	
	
do													
//process message sent from server 		
{ 		 			
try												
//read message and display it 			{ 				

message = (String) input.readObject(); 
				
displayArea.append("\n" + message);
 				displayArea.setCaretPosition(displayArea.getText().length());
 			
} 			
catch(ClassNotFoundException classNotFoundException) 			
{ 				
displayArea.append("\nUnknown object type received"); 			
} 		
}while(!message.equals("TERMINATE")); 		 	
}//end method process connection 	 	

private void closeConnection() throws IOException		
//close streams and socket 	
{ 		
displayArea.append("\nClosing connection"); 		
output.close(); 		
input.close(); 		
client.close(); 	
} 	 	
private void sendData(String message)				
//send message to server 	
{ 		
try												//send object to sever 		
{ 			
output.writeObject("" + message); 			
output.flush(); 			
displayArea.append("\n" + message); 		
} 		
catch(IOException ioException)				
//process problems sending object 		
{ 			
displayArea.append("\nError writing object"); 		
} 	
} 
}//end class Client

import java.io.*; 
import java.net.*; 
import java.awt.*; 
import java.awt.event.*; 
import javax.swing.*;  

public class Server 
{ 	
private ObjectOutputStream output; 	
private ObjectInputStream input; 	
private ServerSocket server; 
private Socket connection; 	
private int counter = 1; 	
private String file1; 	 	
public static void main( String args[] )		
// execute application 	
{ 		
Server application = new Server(); 		
application.runServer(); 	
} 	 	
public Server() 	
{ 		 	
}  	
// set up and run server  	
public void runServer() 
{ 		
try		
// set up server to receive connections & process connections 		
{ 			
server = new ServerSocket( 8189, 50 );		
// Step 1: Create a ServerSocket. 	
		 			
while ( true )  			
{ 				
waitForConnection();					
// Step 2: Wait for a connection. 				
getStreams();							
// Step 3: Get input and output streams. 				
processConnection();					
// Step 4: Process connection. 				
closeConnection();						
// Step 5: Close connection. 				
//++counter; 			
} 		
} 		
catch ( EOFException eofException )	
// process EOFException when client closes connection 		
{ 			
System.out.println( "Client terminated connection" ); 		
} 		
catch ( IOException ioException ) 		
// process problems with I/O 		
{ 			
ioException.printStackTrace(); 		
} 	
} 	 	
private void waitForConnection() throws IOException		
// wait for connection to arrive, then display connection info 	
{ 		
System.out.println( "Waiting for connection\n" ); 		
connection = server.accept();							
// allow server to accept a connection 		
System.out.println( "Connection " + counter + " received from: " + connection.getInetAddress().getHostName() ); 	
} 	 	
private void getStreams() throws IOException			
// get streams to send and receive data 	
{ 		
output = new ObjectOutputStream( connection.getOutputStream() );	
// set up output stream for objects 		
output.flush();											
// flush output buffer to send header information 		
input = new ObjectInputStream( connection.getInputStream() );		
// set up input stream for objects 	
} 	 	
// process connection with client 	

private void processConnection() throws IOException 	
{ 		
String message = "SERVER>>> Connection successful, Please name the file";		
// send connection successful message to client 		
output.writeObject( message ); 		
output.flush(); 		 		

do  		
{				
// process messages sent from client 			
try  			
{	 				
message = ( String ) input.readObject();	
// read message and display it 				
File file1 = new File(message); 				
if(file1.exists() && file1.isFile()) 				
{ 					
BufferedReader in = new BufferedReader(new FileReader(file1)); 					
//String myFile = ""; 					
String line = in.readLine(); 							            	 					
while(line != null) 					
{ 						
//myFile += line + "\n"; 						
line = in.readLine(); 						
System.out.println("" + line); 					
}    	 					

in.close(); 				
} 				
else 				
{ 					
System.out.println("File does not exist"); 				
} 			
} 			
catch ( ClassNotFoundException classNotFoundException ) 	
// catch problems reading from client 			
{ 				
System.out.println( "\nUnknown object type received" ); 			
} 		
} while ( !message.equals( "TERMINATE" ) ); 	
} 	 	
private void closeConnection() throws IOException		
// close streams and socket 	
{ 		
System.out.println( "\nUser terminated connection" ); 		
output.close(); 		
input.close(); 		
connection.close(); 	
} 	 	 	

private void sendData( String message )			
// send message to client 	
{ 		
try 		
// send object to client 		
{ 			
output.writeObject( "SERVER>>> " + message ); 			
output.flush(); 			
//System.out.println( "\nSERVER>>>" + message ); 		
} 		
catch ( IOException ioException ) 			
// process problems sending object 		
{ 			
System.out.println( "\nError writing object" ); 		
} 	
} 
}  // end class Server