se.kth.leiflindback.distdb.db
Class DBHandler

java.lang.Object
  org.jgroups.ReceiverAdapter
      se.kth.leiflindback.distdb.db.DBHandler

All Implemented Interfaces:

org.jgroups.MembershipListener, org.jgroups.MessageListener, org.jgroups.Receiver

public class DBHandler
extends org.jgroups.ReceiverAdapter

This class handles all communication betwwen clients and database (that is, the bank account). UDP multicast is used without any form of delivery control or ordering.

Constructor Summary

DBHandler(Account account)
Creates a new instance that updates the specified account.

Method Summary

byte[]	getState() Called by the jgroups runtime when som other node needs the groups state.
static void	main(java.lang.String[] args) Starts a database server.
void	receive(org.jgroups.Message msg) Called by the jgroups runtime when a message has arrived.
void	setState(byte[] state) Called by the jgroups runtime when this node has requested state info.
void	start(java.lang.String config) Starts the database server.
void	stop() Stops the database server.

Methods inherited from class org.jgroups.ReceiverAdapter

block, suspect, viewAccepted

Methods inherited from class java.lang.Object

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

Constructor Detail

DBHandler

public DBHandler(Account account)

Creates a new instance that updates the specified account.

Parameters:

account - The account managed by this instance.

Method Detail

receive

public void receive(org.jgroups.Message msg)

Called by the jgroups runtime when a message has arrived.

Specified by:

receive in interface org.jgroups.MessageListener

Overrides:

receive in class org.jgroups.ReceiverAdapter

Parameters:

msg - The newly arrived message.

getState

public byte[] getState()

Called by the jgroups runtime when som other node needs the groups state.

Specified by:

getState in interface org.jgroups.MessageListener

Overrides:

getState in class org.jgroups.ReceiverAdapter

Returns:

The current state of the group.

setState

public void setState(byte[] state)

Called by the jgroups runtime when this node has requested state info.

Specified by:

setState in interface org.jgroups.MessageListener

Overrides:

setState in class org.jgroups.ReceiverAdapter

Parameters:

state - The current state of the group.

stop

public void stop()

Stops the database server.

start

public void start(java.lang.String config)

Starts the database server.

Parameters:

config - The jgroups configuration. This string is passed to the JChannel constructor.

main

public static void main(java.lang.String[] args)

Starts a database server.