org.jgroups.demos

Class QuoteServer

java.lang.Object

org.jgroups.ReceiverAdapter

org.jgroups.demos.QuoteServer

All Implemented Interfaces:

MembershipListener, MessageListener, Receiver

public class QuoteServer
extends ReceiverAdapter

Example of a replicated quote server. The server maintains state which consists of a list of quotes and their corresponding values. When it is started, it tries to reach other quote servers to get its initial state. If it does not receive any response after 5 seconds, it assumes it is the first server and starts processing requests.

Any updates are multicast across the cluster

Author:

Bela Ban

Constructor Summary

Constructors

Constructor and Description
QuoteServer()

Method Summary

Methods

Modifier and Type	Method and Description
Hashtable	getAllStocks()
float	getQuote(String stock_name)
void	getState(OutputStream ostream) Allows an application to write a state through a provided OutputStream.
static void	main(String[] args)
void	printAllStocks()
void	setQuote(String stock_name, Float value)
void	setState(InputStream istream) Allows an application to read a state through a provided InputStream.
void	start()
void	viewAccepted(View new_view) Called when a change in membership has occurred.

Methods inherited from class org.jgroups.ReceiverAdapter

block, receive, suspect, unblock

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

QuoteServer

public QuoteServer()

Method Detail

viewAccepted

public void viewAccepted(View new_view)

Description copied from class: ReceiverAdapter

Called when a change in membership has occurred. No long running actions, sending of messages or anything that could block should be done in this callback. If some long running action needs to be performed, it should be done in a separate thread.

Note that on reception of the first view (a new member just joined), the channel will not yet be in the connected state. This only happens when Channel.connect(String) returns.

Specified by:

viewAccepted in interface MembershipListener

Overrides:

viewAccepted in class ReceiverAdapter

start

public void start()

getQuote

public float getQuote(String stock_name)
               throws Exception

Throws:

Exception

setQuote

public void setQuote(String stock_name,
            Float value)

getAllStocks

public Hashtable getAllStocks()

printAllStocks

public void printAllStocks()

getState

public void getState(OutputStream ostream)
              throws Exception

Description copied from class: ReceiverAdapter

Allows an application to write a state through a provided OutputStream. After the state has been written the OutputStream doesn't need to be closed as stream closing is automatically done when a calling thread returns from this callback.

Specified by:

getState in interface MessageListener

Overrides:

getState in class ReceiverAdapter

Parameters:

ostream - the OutputStream

Throws:

Exception - if the streaming fails, any exceptions should be thrown so that the state requester can re-throw them and let the caller know what happened

See Also:

OutputStream.close()

setState

public void setState(InputStream istream)
              throws Exception

Description copied from class: ReceiverAdapter

Allows an application to read a state through a provided InputStream. After the state has been read the InputStream doesn't need to be closed as stream closing is automatically done when a calling thread returns from this callback.

Specified by:

setState in interface MessageListener

Overrides:

setState in class ReceiverAdapter

Parameters:

istream - the InputStream

Throws:

Exception - if the streaming fails, any exceptions should be thrown so that the state requester can catch them and thus know what happened

See Also:

InputStream.close()

main

public static void main(String[] args)