net.sf.basedb.core.signal
Class SocketSignalReceiver

java.lang.Object
  net.sf.basedb.core.signal.AbstractSignalReceiver
      net.sf.basedb.core.signal.SocketSignalReceiver

All Implemented Interfaces:

SignalReceiver

Direct Known Subclasses:

AgentSignalReceiver

public class SocketSignalReceiver
extends AbstractSignalReceiver

A signal receiver implementation that listens on a socket for incoming signals. Accordingly, this receiver supports sending signals between different virtual machines running on different servers. The initialisation string for this class should be of the format:

port=xx&proxy=host:port&forward=xx&allow=ip-address&allow=ip-address...

where:

• The port is the port number the signal receiver will listen on. This is optional and if not given a random non-used port will be used.
• The proxy is the address of a proxy host that will route incoming messages to this signal receiver. The proxy will automatically be added to the list of allowed hosts. This value is optional.
• The forward attribute is a boolean option (1 or 0). If 1, this signal receiver will act as a proxy and forward signal messages which are of the form:

  signal://handlerID@host:port/?SIGNAL#forward.to.host:port

  Before the message is forwarded it is re-built like this:

  signal://handlerId@forward.to.host:port/?SIGNAL

• The allow parts are the ip name or numbers of hosts that are allowed to send signals to the receiver. Except for the special case allow=*, which allows any remote host to send signals an exact match is required. The local host is always allowed to send signals.

  If no allow tags are given only allow connections from the local host (and the proxy if given) are allowed.

Version:

2.6

Author:

nicklas

Last modified

$Date: 2008-09-11 22:09:17 +0200 (Thu, 11 Sep 2008) $

Nested Class Summary

private class

SocketSignalReceiver.ListenerThread This class is used for listening to the specified socket for incoming connections.

Field Summary

private Set<InetAddress>	allow
private boolean	allowAll
private boolean	allowForward
private InetAddress	ip
private Thread	listener
private static Logger	logger Log signals processing.
private int	port
private String	proxy

Constructor Summary

SocketSignalReceiver()
Create a new socket signal receiver.

Method Summary

void	close(int wait) Close this receiver and the socket it is listening on.
protected boolean	forwardSignalMessageIfNeeded(String message) If the message has forwarding information, forward the message to the other host.
protected String	getGlobalSignalId(SignalHandler handler) Override ID generation so we can add proxy information if needed.
Class<? extends SignalTransporter>	getSignalTransporterClass() Get the signal transporter class that should be used to send signals to this receiver.
void	init(String params) Initialise the receiver.
protected boolean	isAllowedHost(InetAddress remoteHost) Checks if the specified remote host is allowed to send signals to this receiver.
protected void	listenOnSocket() Start listening for incoming signals.
protected void	parseInitParameters(String params) Parse the initialisation parameters.
protected void	processSignalMessage(String message) Process the incoming message.

Methods inherited from class net.sf.basedb.core.signal.AbstractSignalReceiver

getLocalSignalHandlerId, getReceiverId, getSignalHandler, registerSignalHandler, sendToAll, sendToAll, unregisterSignalHandler

Methods inherited from class java.lang.Object

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

Field Detail

logger

private static final Logger logger

Log signals processing.

ip

private InetAddress ip

listener

private Thread listener

port

private int port

proxy

private String proxy

allowForward

private boolean allowForward

allow

private Set<InetAddress> allow

allowAll

private boolean allowAll

Constructor Detail

SocketSignalReceiver

public SocketSignalReceiver()

Create a new socket signal receiver. Before it can be used it must be initialised with init(String).

Method Detail

init

public void init(String params)

Initialise the receiver. The given parameter should be the port number the receiver should listen on. If the parameter can't be parsed as a numeric value, a random free port will be used. This method will open the socket and start a separate thread that listens for incoming signals.

Specified by:

init in interface SignalReceiver

Overrides:

init in class AbstractSignalReceiver

Parameters:

params - The ID of the signal receiver, needed if the default ID generation should be used

getSignalTransporterClass

public Class<? extends SignalTransporter> getSignalTransporterClass()

Description copied from interface: SignalReceiver

Get the signal transporter class that should be used to send signals to this receiver.

Returns:

SocketSignalTransporter

close

public void close(int wait)

Close this receiver and the socket it is listening on.

Specified by:

close in interface SignalReceiver

Overrides:

close in class AbstractSignalReceiver

Parameters:

wait - Number of milliseconds to wait for registered jobs to abort, use a negative value to disable notification, and 0 to disable waiting

getGlobalSignalId

protected String getGlobalSignalId(SignalHandler handler)

Override ID generation so we can add proxy information if needed.

Overrides:

getGlobalSignalId in class AbstractSignalReceiver

Parameters:

handler - The signal handler to generate the ID for

Returns:

The signal handler ID

processSignalMessage

protected void processSignalMessage(String message)

Process the incoming message. This class will check if the message contains any forwarding information. If so, the message will be forwarde to the new destination. Otherwise, the message will be processed as normal.

Overrides:

processSignalMessage in class AbstractSignalReceiver

Parameters:

message - The message to process, the format of the message must be compatible with the message that AbstractSignalTransporter.generateSignalMessage(Signal) generates

parseInitParameters

protected void parseInitParameters(String params)

Parse the initialisation parameters. Called from the init(String) method.

Parameters:

params - Parameter string passed to init(String) method

listenOnSocket

protected void listenOnSocket()

Start listening for incoming signals.

forwardSignalMessageIfNeeded

protected boolean forwardSignalMessageIfNeeded(String message)

If the message has forwarding information, forward the message to the other host.

Returns:

TRUE if the message was forwarded, FALSE otherwise

isAllowedHost

protected boolean isAllowedHost(InetAddress remoteHost)

Checks if the specified remote host is allowed to send signals to this receiver.

Parameters:

remoteHost - The remote host that is sending the signal

Returns:

TRUE if the host is allowed, FALSE otherwise