org.jgroups.demos.ReplicatedHashMapDemo Maven / Gradle / Ivy
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This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including
all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and
JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up
with different versions on classes on the class path).
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 {
ReplicatedHashMap 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 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<>(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 {
switch(command) {
case "Get": {
String stock_name=stock_field.getText();
if(stock_name == null || stock_name.isEmpty()) {
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");
}
break;
}
case "Set":
String stock_name=stock_field.getText();
String stock_val=value_field.getText();
if(stock_name == null || stock_val == null || stock_name.isEmpty() ||
stock_val.isEmpty()) {
showMsg("Both key and value have to be present to create a new entry");
return;
}
Float val=Float.parseFloat(stock_val);
map.put(stock_name, val);
showMsg("Key " + stock_name + " set to " + val);
break;
case "All":
showAll();
break;
case "Quit":
setVisible(false);
System.exit(0);
case "Delete":
removeItem();
break;
default:
System.out.println("Unknown action");
break;
}
}
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 m) {
System.out.println("new contents: " + m);
}
public void contentsCleared() {
System.out.println("contents cleared");
}
public void viewChange(View view, java.util.List new_mbrs, java.util.List old_mbrs) {
System.out.println("** view: " + view);
_setTitle();
}
private void _setTitle() {
int num=map.getChannel().getView().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 ]");
}
}