// $Id: DistributedQueueDemo.java,v 1.6 2004/09/23 16:29:35 belaban Exp $
package org.jgroups.demos;
import org.jgroups.ChannelException;
import org.jgroups.ChannelFactory;
import org.jgroups.JChannelFactory;
import org.jgroups.blocks.DistributedQueue;
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;
import java.util.Collection;
import java.util.Vector;
/**
* Uses the DistributedQueue building block. The latter subclasses org.jgroups.util.Queue and overrides
* the methods that modify the queue (e.g. add()). Those methods are multicast to the group, whereas
* read-only methods such as peek() use the local copy. A DistributedQueue is created given the name
* of a group; all queues with the same name find each other and form a group.
* @author Romuald du Song
*/
public class DistributedQueueDemo extends Frame implements WindowListener, ActionListener,
DistributedQueue.Notification
{
DistributedQueue h = null;
final JButton add = new JButton("Add");
final JButton quit = new JButton("Quit");
final JButton get_all = new JButton("All");
final JButton remove = new JButton("Remove");
final JLabel value = new JLabel("Value");
final JLabel err_msg = new JLabel("Error");
final JTextField value_field = new JTextField();
final java.awt.List listbox = new java.awt.List();
final Font default_font = new Font("Helvetica", Font.PLAIN, 12);
public DistributedQueueDemo()
{
super();
addWindowListener(this);
}
private void showMsg(String msg)
{
err_msg.setText(msg);
err_msg.setVisible(true);
}
private void clearMsg()
{
err_msg.setVisible(false);
}
private void removeItem()
{
h.remove();
}
private void showAll()
{
if (listbox.getItemCount() > 0)
{
listbox.removeAll();
}
if (h.size() == 0)
{
return;
}
clearMsg();
String key;
Vector v = h.getContents();
for (int i = 0; i < v.size(); i++)
{
listbox.add((String)v.elementAt(i));
}
}
public void start(String groupname, ChannelFactory factory, String props)
throws ChannelException
{
h = new DistributedQueue(groupname, factory, props, 10000);
h.addNotifier(this);
setLayout(null);
setSize(400, 300);
setFont(default_font);
value.setBounds(new Rectangle(10, 60, 60, 30));
value_field.setBounds(new Rectangle(100, 60, 100, 30));
listbox.setBounds(new Rectangle(210, 30, 150, 160));
err_msg.setBounds(new Rectangle(10, 200, 350, 30));
err_msg.setFont(new Font("Helvetica", Font.ITALIC, 12));
err_msg.setForeground(Color.red);
err_msg.setVisible(false);
add.setBounds(new Rectangle(60, 250, 60, 30));
quit.setBounds(new Rectangle(130, 250, 70, 30));
get_all.setBounds(new Rectangle(210, 250, 60, 30));
remove.setBounds(new Rectangle(280, 250, 90, 30));
add.addActionListener(this);
quit.addActionListener(this);
get_all.addActionListener(this);
remove.addActionListener(this);
add(value);
add(value_field);
add(err_msg);
add(add);
add(quit);
add(get_all);
add(remove);
add(listbox);
setTitle("DistributedQueue Demo");
showAll();
pack();
setVisible(true);
/*
new Thread() {
public void run() {
System.out.println("-- sleeping");
Util.sleep(10000);
for(int i=0; i < 10; i++) {
System.out.println("-- add()");
h.add("Bela#" + i);
}
while(true) {
Util.sleep(500);
try
{
System.out.println(h.remove());
}
catch (QueueClosedException e)
{
e.printStackTrace();
}
}
}
}.start();
*/
}
public void windowActivated(WindowEvent e)
{
}
public void windowClosed(WindowEvent e)
{
}
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
public void windowDeactivated(WindowEvent e)
{
}
public void windowDeiconified(WindowEvent e)
{
}
public void windowIconified(WindowEvent e)
{
}
public void windowOpened(WindowEvent e)
{
}
public void actionPerformed(ActionEvent e)
{
String command = e.getActionCommand();
try
{
if (command == "Add")
{
String value_name = value_field.getText();
if ((value_name == null) || (value_name.length() == 0))
{
showMsg("Value is empty !");
return;
}
showMsg("Adding value " + value_name + ':');
h.add(value_name);
}
else if (command == "All")
{
showAll();
}
else if (command == "Quit")
{
setVisible(false);
System.exit(0);
}
else if (command == "Remove")
{
removeItem();
}
else
{
System.out.println("Unknown action");
}
}
catch (Exception ex)
{
value_field.setText("");
showMsg(ex.toString());
}
}
public void entryAdd(Object value)
{
showAll();
}
public void entryRemoved(Object key)
{
showAll();
}
public void viewChange(Vector joined, Vector left)
{
System.out.println("New members: " + joined + ", left members: " + left);
}
public void contentsSet(Collection new_entries)
{
System.out.println("Contents Set:" + new_entries);
}
public void contentsCleared()
{
System.out.println("Contents cleared()");
}
public static void main(String[] args)
{
String groupname = "QueueDemo";
DistributedQueueDemo client = new DistributedQueueDemo();
ChannelFactory factory = new JChannelFactory();
String arg;
String next_arg;
boolean trace = false;
boolean persist = false;
String props =
"UDP(mcast_addr=228.8.8.8;mcast_port=45566;ip_ttl=32;" +
"mcast_send_buf_size=150000;mcast_recv_buf_size=80000):" + "PING(timeout=2000;num_initial_members=3):" +
"MERGE2(min_interval=5000;max_interval=10000):" + "FD_SOCK:" + "VERIFY_SUSPECT(timeout=1500):" +
"UNICAST(timeout=5000):" + "FRAG(frag_size=8192;down_thread=false;up_thread=false):" +
"TOTAL_TOKEN(block_sending=50;unblock_sending=10):" +
"pbcast.GMS(join_timeout=5000;join_retry_timeout=2000;" + "shun=false;print_local_addr=true):" +
"STATE_TRANSFER:" + "QUEUE";
try
{
for (int i = 0; i < args.length; i++)
{
arg = args[i];
if ("-trace".equals(arg))
{
trace = true;
continue;
}
if ("-groupname".equals(args[i]))
{
groupname = args[++i];
continue;
}
help();
return;
}
}
catch (Exception e)
{
help();
return;
}
try
{
client.start(groupname, factory, props);
}
catch (Throwable t)
{
t.printStackTrace();
}
}
static void help()
{
System.out.println("DistributedQueueDemo [-help]");
}
}