org.jgroups.demos.Draw 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.*;
import org.jgroups.jmx.JmxConfigurator;
import org.jgroups.stack.AddressGenerator;
import org.jgroups.util.OneTimeAddressGenerator;
import org.jgroups.util.Util;
import javax.management.MBeanServer;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.util.List;
import java.util.*;
/**
* Shared whiteboard, each new instance joins the same group. Each instance chooses a random color,
* mouse moves are broadcast to all group members, which then apply them to their canvas
* @author Bela Ban, Oct 17 2001
*/
public class Draw implements Receiver, ActionListener, ChannelListener {
protected String cluster_name="draw";
private JChannel channel=null;
private int member_size=1;
private JFrame mainFrame=null;
private JPanel sub_panel=null;
private DrawPanel panel=null;
private JButton clear_button, leave_button;
private final Random random=new Random(System.currentTimeMillis());
private final Color draw_color=selectColor();
private static final Color background_color=Color.white;
boolean no_channel=false;
boolean jmx;
private boolean use_state=false;
private long state_timeout=5000;
private boolean use_unicasts=false;
protected boolean send_own_state_on_merge=true;
private final List
members=new ArrayList<>();
public Draw(String props, boolean no_channel, boolean jmx, boolean use_state, long state_timeout,
boolean use_unicasts, String name, boolean send_own_state_on_merge, AddressGenerator gen) throws Exception {
this.no_channel=no_channel;
this.jmx=jmx;
this.use_state=use_state;
this.state_timeout=state_timeout;
this.use_unicasts=use_unicasts;
if(no_channel)
return;
channel=new JChannel(props).addAddressGenerator(gen).setName(name);
channel.setReceiver(this).addChannelListener(this);
this.send_own_state_on_merge=send_own_state_on_merge;
}
public Draw(JChannel channel) throws Exception {
this.channel=channel;
channel.setReceiver(this);
channel.addChannelListener(this);
}
public Draw(JChannel channel, boolean use_state, long state_timeout) throws Exception {
this.channel=channel;
channel.setReceiver(this);
channel.addChannelListener(this);
this.use_state=use_state;
this.state_timeout=state_timeout;
}
public String getClusterName() {
return cluster_name;
}
public void setClusterName(String clustername) {
if(clustername != null)
this.cluster_name=clustername;
}
public static void main(String[] args) {
Draw draw=null;
String props=null;
boolean no_channel=false;
boolean jmx=true;
boolean use_state=false;
String group_name=null;
long state_timeout=5000;
boolean use_unicasts=false;
String name=null;
boolean send_own_state_on_merge=true;
AddressGenerator generator=null;
for(int i=0; i < args.length; i++) {
if("-help".equals(args[i])) {
help();
return;
}
if("-props".equals(args[i])) {
props=args[++i];
continue;
}
if("-no_channel".equals(args[i])) {
no_channel=true;
continue;
}
if("-jmx".equals(args[i])) {
jmx=Boolean.parseBoolean(args[++i]);
continue;
}
if("-clustername".equals(args[i])) {
group_name=args[++i];
continue;
}
if("-state".equals(args[i])) {
use_state=true;
continue;
}
if("-timeout".equals(args[i])) {
state_timeout=Long.parseLong(args[++i]);
continue;
}
if("-use_unicasts".equals(args[i])) {
use_unicasts=true;
continue;
}
if("-name".equals(args[i])) {
name=args[++i];
continue;
}
if("-send_own_state_on_merge".equals(args[i])) {
send_own_state_on_merge=Boolean.getBoolean(args[++i]);
continue;
}
if("-uuid".equals(args[i])) {
generator=new OneTimeAddressGenerator(Long.parseLong(args[++i]));
continue;
}
help();
return;
}
try {
draw=new Draw(props, no_channel, jmx, use_state, state_timeout, use_unicasts, name,
send_own_state_on_merge, generator);
if(group_name != null)
draw.setClusterName(group_name);
draw.go();
}
catch(Throwable e) {
e.printStackTrace(System.err);
System.exit(0);
}
}
static void help() {
System.out.println("\nDraw [-help] [-no_channel] [-props ]" +
" [-clustername ] [-state] [-timeout ] [-use_unicasts] " +
"[-jmx ] [-name ] [-send_own_state_on_merge true|false] " +
"[-uuid ]");
System.out.println("-no_channel: doesn't use JGroups at all, any drawing will be relected on the " +
"whiteboard directly");
System.out.println("-props: argument can be an old-style protocol stack specification, or it can be " +
"a URL. In the latter case, the protocol specification will be read from the URL\n");
}
private Color selectColor() {
int red=Math.abs(random.nextInt() % 255);
int green=Math.abs(random.nextInt() % 255);
int blue=Math.abs(random.nextInt() % 255);
return new Color(red, green, blue);
}
private void sendToAll(byte[] buf) throws Exception {
for(Address mbr: members)
channel.send(new BytesMessage(mbr, buf));
}
public void go() throws Exception {
if(!no_channel && !use_state)
channel.connect(cluster_name);
mainFrame=new JFrame();
mainFrame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
panel=new DrawPanel(use_state);
panel.setBackground(background_color);
sub_panel=new JPanel();
mainFrame.getContentPane().add("Center", panel);
clear_button=new JButton("Clear");
clear_button.addActionListener(this);
leave_button=new JButton("Leave");
leave_button.addActionListener(this);
sub_panel.add("South", clear_button);
sub_panel.add("South", leave_button);
mainFrame.getContentPane().add("South", sub_panel);
mainFrame.setBackground(background_color);
clear_button.setForeground(Color.blue);
leave_button.setForeground(Color.blue);
mainFrame.pack();
mainFrame.setLocation(15, 25);
mainFrame.setBounds(new Rectangle(250, 250));
if(!no_channel && use_state) {
channel.connect(cluster_name, null, state_timeout);
}
mainFrame.setVisible(true);
setTitle();
}
void setTitle(String title) {
String tmp="";
if(no_channel) {
mainFrame.setTitle(" Draw Demo ");
return;
}
if(title != null) {
mainFrame.setTitle(title);
}
else {
if(channel.getAddress() != null)
tmp+=channel.getAddress();
tmp+=" (" + member_size + ")";
mainFrame.setTitle(tmp);
}
}
void setTitle() {
setTitle(null);
}
public void receive(Message msg) {
byte[] buf=msg.getArray();
if(buf == null) {
System.err.printf("%s: received null buffer from %s, headers: %s\n", channel.getAddress(), msg.getSrc(), msg.printHeaders());
return;
}
try {
DrawCommand comm=Util.streamableFromByteBuffer(DrawCommand::new, buf, msg.getOffset(), msg.getLength());
switch(comm.mode) {
case DrawCommand.DRAW:
if(panel != null)
panel.drawPoint(comm);
break;
case DrawCommand.CLEAR:
clearPanel();
break;
default:
System.err.println("***** received invalid draw command " + comm.mode);
break;
}
}
catch(Exception e) {
e.printStackTrace();
}
}
public void viewAccepted(View v) {
member_size=v.size();
if(mainFrame != null)
setTitle();
members.clear();
members.addAll(v.getMembers());
if(v instanceof MergeView) {
System.out.println("** " + v);
// This is an example of a simple merge function, which fetches the state from the coordinator
// on a merge and overwrites all of its own state
if(use_state && !members.isEmpty()) {
Address coord=members.get(0);
Address local_addr=channel.getAddress();
if(local_addr != null && !local_addr.equals(coord)) {
try {
// make a copy of our state first
Map copy=null;
if(send_own_state_on_merge) {
synchronized(panel.state) {
copy=new LinkedHashMap<>(panel.state);
}
}
System.out.println("fetching state from " + coord);
channel.getState(coord, 5000);
if(copy != null)
sendOwnState(copy); // multicast my own state so everybody else has it too
}
catch(Exception e) {
e.printStackTrace();
}
}
}
}
else
System.out.println("** View=" + v);
}
public void getState(OutputStream ostream) throws Exception {
panel.writeState(ostream);
}
public void setState(InputStream istream) throws Exception {
panel.readState(istream);
}
/* --------------- Callbacks --------------- */
public void clearPanel() {
if(panel != null)
panel.clear();
}
public void sendClearPanelMsg() {
DrawCommand comm=new DrawCommand(DrawCommand.CLEAR);
try {
byte[] buf=Util.streamableToByteBuffer(comm);
if(use_unicasts)
sendToAll(buf);
else
channel.send(new BytesMessage(null, buf));
}
catch(Exception ex) {
System.err.println(ex);
}
}
public void actionPerformed(ActionEvent e) {
String command=e.getActionCommand();
switch(command) {
case "Clear":
if(no_channel) {
clearPanel();
return;
}
sendClearPanelMsg();
break;
case "Leave":
stop();
break;
default:
System.out.println("Unknown action");
break;
}
}
public void stop() {
if(!no_channel) {
try {
channel.close();
}
catch(Exception ex) {
System.err.println(ex);
}
}
mainFrame.setVisible(false);
mainFrame.dispose();
}
protected void sendOwnState(final Map copy) {
if(copy == null)
return;
for(Point point: copy.keySet()) {
// we don't need the color: it is our draw_color anyway
DrawCommand comm=new DrawCommand(DrawCommand.DRAW, point.x, point.y, draw_color.getRGB());
try {
byte[] buf=Util.streamableToByteBuffer(comm);
if(use_unicasts)
sendToAll(buf);
else
channel.send(new BytesMessage(null, buf));
}
catch(Exception ex) {
System.err.println(ex);
}
}
}
/* ------------------------------ ChannelListener interface -------------------------- */
public void channelConnected(JChannel channel) {
if(jmx)
Util.registerChannel(channel, "jgroups");
}
public void channelDisconnected(JChannel channel) {
if(jmx) {
MBeanServer server=Util.getMBeanServer();
if(server != null) {
try {
JmxConfigurator.unregisterChannel(channel, server, cluster_name);
}
catch(Exception e) {
e.printStackTrace();
}
}
}
}
/* --------------------------- End of ChannelListener interface ---------------------- */
protected class DrawPanel extends JPanel implements MouseMotionListener {
protected final Dimension preferred_size=new Dimension(235, 170);
protected Image img; // for drawing pixels
protected Dimension d, imgsize;
protected Graphics gr;
protected final Map state;
public DrawPanel(boolean use_state) {
if(use_state)
state=new LinkedHashMap<>();
else
state=null;
createOffscreenImage(false);
addMouseMotionListener(this);
addComponentListener(new ComponentAdapter() {
public void componentResized(ComponentEvent e) {
if(getWidth() <= 0 || getHeight() <= 0) return;
createOffscreenImage(false);
}
});
}
public void writeState(OutputStream outstream) throws IOException {
if(state == null)
return;
synchronized(state) {
DataOutputStream dos=new DataOutputStream(new BufferedOutputStream(outstream));
// DataOutputStream dos=new DataOutputStream(outstream);
dos.writeInt(state.size());
for(Map.Entry entry: state.entrySet()) {
Point point=entry.getKey();
Color col=entry.getValue();
dos.writeInt(point.x);
dos.writeInt(point.y);
dos.writeInt(col.getRGB());
}
dos.flush();
System.out.println("wrote " + state.size() + " elements");
}
}
public void readState(InputStream instream) throws IOException {
DataInputStream in=new DataInputStream(new BufferedInputStream(instream));
Map new_state=new LinkedHashMap<>();
int num=in.readInt();
for(int i=0; i < num; i++) {
Point point=new Point(in.readInt(), in.readInt());
Color col=new Color(in.readInt());
new_state.put(point, col);
}
synchronized(state) {
state.clear();
state.putAll(new_state);
System.out.println("read " + state.size() + " elements");
createOffscreenImage(true);
}
}
void createOffscreenImage(boolean discard_image) {
d=getSize();
if(discard_image) {
img=null;
imgsize=null;
}
if(img == null || imgsize == null || imgsize.width != d.width || imgsize.height != d.height) {
img=createImage(d.width, d.height);
if(img != null) {
gr=img.getGraphics();
if(gr != null && state != null) {
drawState();
}
}
imgsize=d;
}
repaint();
}
/* ---------------------- MouseMotionListener interface------------------------- */
public void mouseMoved(MouseEvent e) {}
public void mouseDragged(MouseEvent e) {
int x=e.getX(), y=e.getY();
DrawCommand comm=new DrawCommand(DrawCommand.DRAW, x, y, draw_color.getRGB());
if(no_channel) {
drawPoint(comm);
return;
}
try {
byte[] buf=Util.streamableToByteBuffer(comm);
if(use_unicasts)
sendToAll(buf);
else
channel.send(new BytesMessage(null, buf));
}
catch(Exception ex) {
System.err.println(ex);
}
}
/* ------------------- End of MouseMotionListener interface --------------------- */
/**
* Adds pixel to queue and calls repaint() whenever we have MAX_ITEMS pixels in the queue
* or when MAX_TIME msecs have elapsed (whichever comes first). The advantage compared to just calling
* repaint() after adding a pixel to the queue is that repaint() can most often draw multiple points
* at the same time.
*/
public void drawPoint(DrawCommand c) {
if(c == null || gr == null) return;
Color col=new Color(c.rgb);
gr.setColor(col);
gr.fillOval(c.x, c.y, 10, 10);
repaint();
if(state != null) {
synchronized(state) {
state.put(new Point(c.x, c.y), col);
}
}
}
public void clear() {
if(gr == null) return;
gr.clearRect(0, 0, getSize().width, getSize().height);
repaint();
if(state != null) {
synchronized(state) {
state.clear();
}
}
}
/** Draw the entire panel from the state */
public void drawState() {
synchronized(state) {
for(Iterator it=state.entrySet().iterator(); it.hasNext();) {
Map.Entry entry=(Map.Entry)it.next();
Point pt=entry.getKey();
Color col=entry.getValue();
gr.setColor(col);
gr.fillOval(pt.x, pt.y, 10, 10);
}
}
repaint();
}
public Dimension getPreferredSize() {
return preferred_size;
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
if(img != null) {
g.drawImage(img, 0, 0, null);
}
}
}
}