receiveclient.java

RMI asynchronism receive message callback() register and deregister to control update or interrupt

package client;

import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.rmi.RemoteException;
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;
import java.rmi.server.UnicastRemoteObject;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;

import both.CallBack;
import both.Stock;

public class ReceiveClient extends JFrame implements CallBack, ActionListener{
	private static final long serialVersionUID = 1L;
	private JLabel lm = new JLabel("Receive Client");
    private Font f=new Font("TimesNewRoman",Font.BOLD,24);
	private JLabel l1=new JLabel("Stock Symbol");
	private JLabel l2= new JLabel("Value");
	private JTextField t1 = new JTextField("");
	private JTextField t2 = new JTextField("");
	private JButton b1 = new JButton("Callback");
	private JButton b2 = new JButton("interrupt");
	CallBack c = null;
	Stock a = null;
	
		public ReceiveClient(){
			this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	    	this.setLayout(null);
	    	lm.setFont(f);
	    	this.add(lm); lm.setBounds(50,10,200,30);
	    	this.add(l1); l1.setBounds(30,50,100,30);
	    	this.add(t1); t1.setBounds(30,90,200,30);
	    	this.add(l2); l2.setBounds(30,130,100,30);
	    	this.add(t2); t2.setBounds(30,170,200,30);
	    	this.add(b1); b1.setBounds(30,220,90,30);
	    	b1.addActionListener(this);
	    	this.add(b2); b2.setBounds(150,220,90,30);
	    	b2.addActionListener(this);
	    	setSize(280,300);
			setVisible(true);
	    	try{
	    	Registry registry = LocateRegistry.getRegistry(null);
			 a = (Stock) registry.lookup("Stock");
			 c = (CallBack) UnicastRemoteObject.exportObject(ReceiveClient.this, 0);
			} catch (Exception ex) {
				System.err.println("Client exception: " + ex.toString());
				ex.printStackTrace();}
		}
			 
		public void actionPerformed(ActionEvent evt) {
			Object source = evt.getSource();
			if (source == b1){
				try {
					a.register(c);
				}catch (RemoteException e1){
					e1.printStackTrace();}
			} 
			else if (source == b2){
				try {
					a.interrupt(c);
				}catch (Exception ex){
					System.err.println("Client exception: " + ex.toString());
					ex.printStackTrace();}
			}
		}
		
		public void callBack(String stockSymbol, int value) throws RemoteException {
			t1.setText(stockSymbol);
			t2.setText(Integer.toString(value));
		}
		
		public static void main(String[] args) {
			System.out.println("Receive Ready");
			new ReceiveClient();}
}