package org.jgroups.demos;
import org.jgroups.Address;
import org.jgroups.JChannel;
import org.jgroups.View;
import org.jgroups.blocks.ReplicatedHashMap;
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.Map;
/**
* Uses the ReplicatedHashMap building block, which subclasses java.util.HashMap and overrides
* the methods that modify the hashmap (e.g. put()). Those methods are multicast to the group, whereas
* read-only methods such as get() use the local copy. A ReplicatedtHashMap is created given the name
* of a group; all hashmaps with the same name find each other and form a group.
* @author Bela Ban
*/
public class ReplicatedHashMapDemo extends Frame implements WindowListener, ActionListener, ReplicatedHashMap.Notification<Object,Object> {
ReplicatedHashMap<String,Float> map=null;
final JButton get=new JButton("Get");
final JButton set=new JButton("Set");
final JButton quit=new JButton("Quit");
final JButton get_all=new JButton("All");
final JButton delete=new JButton("Delete");
final JLabel stock=new JLabel("Key");
final JLabel value=new JLabel("Value");
final JLabel err_msg=new JLabel("Error");
final JTextField stock_field=new JTextField();
final JTextField value_field=new JTextField();
final List listbox=new List();
final Font default_font=new Font("Helvetica", Font.PLAIN,12);
public ReplicatedHashMapDemo() {
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() {
int index=listbox.getSelectedIndex();
if(index == -1) {
showMsg("No item selected in listbox to be deleted !");
return;
}
String s=listbox.getSelectedItem();
String key=s.substring(0, s.indexOf(':', 0));
if(key != null)
map.remove(key);
}
private void showAll() {
if(listbox.getItemCount() > 0)
listbox.removeAll();
if(map.isEmpty())
return;
clearMsg();
String key;
Float val;
for(Map.Entry<String,Float> entry: map.entrySet()) {
key=entry.getKey();
val=entry.getValue();
if(val == null)
continue;
listbox.add(key + ": " + val.toString());
}
}
public void start(JChannel channel) throws Exception {
map=new ReplicatedHashMap<String,Float>(channel);
map.addNotifier(this);
map.start(10000);
setLayout(null);
setSize(400, 300);
setFont(default_font);
stock.setBounds(new Rectangle(10, 30, 60, 30));
value.setBounds(new Rectangle(10, 60, 60, 30));
stock_field.setBounds(new Rectangle(100, 30, 100, 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);
get.setBounds(new Rectangle(10, 250, 60, 30));
set.setBounds(new Rectangle(80, 250, 60, 30));
quit.setBounds(new Rectangle(150, 250, 60, 30));
get_all.setBounds(new Rectangle(220, 250, 60, 30));
delete.setBounds(new Rectangle(290, 250, 80, 30));
get.addActionListener(this);
set.addActionListener(this);
quit.addActionListener(this);
get_all.addActionListener(this);
delete.addActionListener(this);
add(stock); add(value);
add(stock_field); add(value_field);
add(err_msg);
add(get); add(set); add(quit); add(get_all); add(delete);
add(listbox);
_setTitle();
showAll();
setVisible(true);
}
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.equals("Get")) {
String stock_name=stock_field.getText();
if(stock_name == null || stock_name.length() == 0) {
showMsg("Key is empty !");
return;
}
showMsg("Looking up value for " + stock_name + ':');
Float val=map.get(stock_name);
if(val != null) {
value_field.setText(val.toString());
clearMsg();
}
else {
value_field.setText("");
showMsg("Value for " + stock_name + " not found");
}
}
else if(command.equals("Set")) {
String stock_name=stock_field.getText();
String stock_val=value_field.getText();
if(stock_name == null || stock_val == null || stock_name.length() == 0 ||
stock_val.length() == 0) {
showMsg("Both key and value have to be present to create a new entry");
return;
}
Float val=new Float(stock_val);
map.put(stock_name, val);
showMsg("Key " + stock_name + " set to " + val);
}
else if(command.equals("All")) {
showAll();
}
else if(command.equals("Quit")) {
setVisible(false);
System.exit(0);
}
else if(command.equals("Delete"))
removeItem();
else
System.out.println("Unknown action");
}
catch(Exception ex) {
value_field.setText("");
showMsg(ex.toString());
}
}
public void entrySet(Object key, Object value) {
showAll();
}
public void entryRemoved(Object key) {
showAll();
}
public void contentsSet(Map<Object,Object> m) {
System.out.println("new contents: " + m);
}
public void contentsCleared() {
System.out.println("contents cleared");
}
public void viewChange(View view, java.util.List<Address> new_mbrs, java.util.List<Address> old_mbrs) {
System.out.println("** view: " + view);
_setTitle();
}
private void _setTitle() {
int num=map.getChannel().getView().getMembers().size();
setTitle("ReplicatedHashMapDemo: " + num + " server(s)");
}
public static void main(String args[]) {
ReplicatedHashMapDemo client=new ReplicatedHashMapDemo();
JChannel channel;
String props="udp.xml";
try {
for(int i=0; i < args.length; i++) {
String arg=args[i];
if("-props".equals(arg)) {
props=args[++i];
continue;
}
help();
return;
}
}
catch(Exception e) {
help();
return;
}
try {
channel=new JChannel(props);
channel.connect("ReplicatedHashMapDemo-Cluster");
client.start(channel);
}
catch(Throwable t) {
t.printStackTrace();
}
}
static void help() {
System.out.println("ReplicatedHashMapDemo [-help] [-props <properties>]");
}
}