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Class com.sun.jaw.impl.agent.services.jawdiscovery.DiscoveryResponder

java.lang.Object
   |
   +----com.sun.jaw.impl.agent.services.jawdiscovery.DiscoveryResponder

public class DiscoveryResponder

extends Object

implements Serializable, ActivatableIf

When a DiscoveryResponder is registered in the framework, or when performStart method is called, the m-bean starts a thread which creates a multicast socket. The DiscoveryResponder then sends a join message to the multicast group. When a DiscoveryResponder is deleted from the framework, or when performStop method is called, the m-bean sends a leave message to the multicast group. The format of these messages is not exposed. These messages allow DiscoveryMonitor objects to maintain a list of agents with DiscoveryResponder objects registered in their frameworks. When a DiscoveryResponder has registered in the framework -or when performStart method is called - and a join message has been sent, the DiscoveryResponder starts to listen for discovery requests.

The multicast socket uses the group and port specified by the properties multicastGroup and multicastPort. The default values for the group and the port are 224.224.224.224 and 9000. These values can be changed when the DiscoveryResponder is registered in the framework by specifying the group and port keys in the ObjectName. These values can be also changed using setMulticastGroup and setMulticastPort methods when the DiscoveryResponder is OFFLINE

When join/leave message are sent to the multicast group, a default time-to-live (see java.net.MulticastSocket) value is used. The time-to-live value specifies how many "hops" that the packet is forwarded on the network before it expires. DiscoveryResponder objects use a time-to-live specified by the property ttl. The default time-to-live value is 1. This can be changed when the DiscoveryResponder is registered in the framework by specifying the ttl keys in the ObjectName. It can be be also changed using setTimeToLive method when the DiscoveryResponder is OFFLINE

For example, to register a DiscoveryResponder that uses the group 224.224.224.222, port 4404 and sends multicast join and leave messages through 4 hops, use the following object name:

domain:com.sun.jaw.impl.agent.services.jawdiscovery.DiscoveryResponder.group=224.224.224.222,port=4404,ttl=4

See Also:

DiscoveryClient

OFFLINE

ONLINE

STOPPING

DiscoveryResponder()

For Java DMK internal use only.

DiscoveryResponder(Framework)

Class constructor.

deleteCmf()

For Java DMK internal use only.

getClassVersion()

Returns the version of this class.

getMulticastGroup()

Returns the multicast group.

getMulticastPort()

Returns the multicast port.

getState()

Returns the state of this DiscoveryResponder.

getStateString()

Returns the state of this DiscoveryResponder in string form.

getTimeToLive()

Returns the time-to-live value.

initCmf(Framework, ObjectName, boolean, ModificationList)

For Java DMK internal use only.

isActive()

Tests if the AdaptorServer is active.

performStart()

performStop()

setMulticastGroup(String)

Sets the multicast group name.

setMulticastPort(int)

Sets the multicast port.

setTimeToLive(int)

Sets the default Time to Live to be used to send join and leave message to the Multicast group.

 public static final int ONLINE

 public static final int OFFLINE

 public static final int STOPPING

 public DiscoveryResponder()

For Java DMK internal use only.

 public DiscoveryResponder(Framework cmf)

Class constructor. Creates a discovery responder using the default multicast group (224.224.224.224) and the default multicast port (9000). The multicast group and port values can be overwritten using setter the properties multicastGroup and multicastPort.

Parameters:

cmf - The actual JDMK framework object.

 public void initCmf(Framework cmf,
                     ObjectName name,
                     boolean db,
                     ModificationList list) throws IllegalAccessException, ServiceNotFoundException, InstanceAlreadyExistException

For Java DMK internal use only.

 public void deleteCmf() throws InstanceNotFoundException, IllegalAccessException, ServiceNotFoundException

For Java DMK internal use only.

 public void performStart()

 public void performStop()

 public boolean isActive()

Tests if the AdaptorServer is active.

 public String getClassVersion()

Returns the version of this class.

Returns:

The version of this class.

 public String getMulticastGroup()

Returns the multicast group.

Returns:

A string containing the multicast group name.

 public void setMulticastGroup(String multicastGroup)

Sets the multicast group name. Only available if state in OFFLINE

Parameters:

multicastGroup - The multicast group name.

 public int getMulticastPort()

Returns the multicast port.

Returns:

The multicast port number.

 public void setMulticastPort(int multicastPort)

Sets the multicast port. Only available if state in OFFLINE

Parameters:

multicastPort - The multicast port.

 public int getTimeToLive()

Returns the time-to-live value.

Returns:

The time-to-live value.

 public void setTimeToLive(int ttl)

Sets the default Time to Live to be used to send join and leave message to the Multicast group. Time to Live should an integer verifying the following condition: 0 < ttl <= 255 Only available if state in OFFLINE

Parameters:

ttl - The Time to live value.

 public Integer getState()

Returns the state of this DiscoveryResponder.

Returns:

ONLINE, OFFLINE or STOPPING.

 public String getStateString()

Returns the state of this DiscoveryResponder in string form.

Returns:

One of the strings "ONLINE", "OFFLINE" or "STOPPING".

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