RMI-applets - Cannot understand error message
- by aeter
In a simple RMI game I'm writing (an assignment in uni), I reveice:
java.rmi.MarshalException: error marshalling arguments; nested exception is:
java.net.SocketException: Broken pipe
at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:138)
at java.rmi.server.RemoteObjectInvocationHandler.invokeRemoteMethod(RemoteObjectInvocationHandler.java:178)
at java.rmi.server.RemoteObjectInvocationHandler.invoke(RemoteObjectInvocationHandler.java:132)
at $Proxy2.drawWorld(Unknown Source)
at PlayerServerImpl$1.actionPerformed(PlayerServerImpl.java:180)
at javax.swing.Timer.fireActionPerformed(Timer.java:271)
at javax.swing.Timer$DoPostEvent.run(Timer.java:201)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:597)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)
The error message appears after the second Player is registered with the RMI Server and the server starts to send the image (the array of pixels) to the 2 applets. The PlayerImpl and the PlayerServerImpl both extend UnicastRemoteObject.
I have been struggling with other error messages for some time now, but I cannot understand how to troubleshoot this one. Please help.
The relevant parts of the code are:
PlayerServerImpl.java:
...
timer = new Timer(10, new ActionListener() { // every 10 milliseconds do:
@Override
public void actionPerformed(ActionEvent e) {
...
BufferedImage buff_image = new BufferedImage(GAME_APPLET_WIDTH, GAME_APPLET_HEIGHT, BufferedImage.TYPE_INT_RGB);
// create a graphics context on the buffered image
Graphics buff_g = buff_image.createGraphics();
...
// draw the score somewhere on the screen
buff_g.drawString(score, GAME_APPLET_WIDTH - 20, 10);
...
int[] rgbs = new int[GAME_APPLET_WIDTH * GAME_APPLET_HEIGHT];
int imgPixelsGrabbed[] = buff_image.getRGB(0,0,GAME_APPLET_WIDTH,GAME_APPLET_HEIGHT,rgbs,0,GAME_APPLET_WIDTH);
// send the new state to the applets
for (Player player : players) {
player.drawWorld(imgPixelsGrabbed);
System.out.println("Sent image to player");
}
PlayerImpl.java:
private PlayerApplet applet;
public PlayerImpl(PlayerApplet applet) throws RemoteException {
super();
this.applet = applet;
}
...
@Override
public void drawWorld(int[] imgPixelsGrabbed) throws RemoteException {
applet.setWorld(imgPixelsGrabbed);
applet.repaint();
}
...
PlayerApplet.java:
...
private int[] world; // an array of pixels for the new image to be drawn
...
// register players
player = new PlayerImpl(applet);
String serverIPAddressPort = ipAddressField.getText();
if (validateIPAddressPort(serverIPAddressPort)) {
server = (PlayerServer) Naming.lookup("rmi://"
+ serverIPAddressPort + "/PlayerServer");
server.register(player);
idPlayer = server.sendPlayerID();
...
@Override
public void update(Graphics g) {
buff_img = createImage((ImageProducer) new MemoryImageSource(getWidth(), getHeight(), world, 0, getWidth()));
Graphics gr = buff_img.getGraphics();
paint(gr);
g.drawImage(buff_img, 0, 0, this);
}
public void setWorld(int[] world) {
this.world = world;
}
