org.jcsp.net

Class ProtocolID

java.lang.Object

org.jcsp.net.ProtocolID

All Implemented Interfaces:

java.io.Serializable

Direct Known Subclasses:

TCPIPProtocolID

public abstract class ProtocolID
extends java.lang.Object
implements java.io.Serializable

Abstract class that identifies a protocol. Provides methods for obtaining the protocol's Builder to be installed in the LinkFactory, starting a LinkServer for this protocol and for creating a NodeAddressID for this protocol from a String.

Protocols must not make use of the NodeID so that protocols can be installed before the node ID is determined. The current definition of TCPIPv4 protocol meets this criteria. Such a change will allow the UIFactory or other initialisation details to be obtained from a central server.

Author:

Quickstone Technologies Limited

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
ProtocolID()

Method Summary

Modifier and Type	Method and Description
protected abstract NodeAddressID	createAddressID(java.lang.String stAddressID, boolean uniqueAddress) Constructs a NodeAddressID from a String.
boolean	equals(java.lang.Object o) This tests whether another object is equal to this object.
protected abstract LinkFactory.Builder	getLinkBuilder(java.util.Hashtable settings) Obtains the Builder for this protocol.
int	getPosition() Gets the position of this protocol in the order of preference.
int	hashCode() Returns a hash code for this object.
abstract boolean	isActive() Not currently used.
abstract boolean	requiresUserInteraction() Returns whether the protocol requires user interaction in order for data to be delivered.
protected abstract LinkServer	startLinkServer(NodeAddressID addressID) Constructs, starts and returns a LinkServer on a specified NodeAddressID.

Methods inherited from class java.lang.Object

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

Constructor Detail

ProtocolID

public ProtocolID()

Method Detail

equals

public boolean equals(java.lang.Object o)

This tests whether another object is equal to this object. Two ProtocolID objects are equal if their classes are the same. This is a default implementation, it is probably more efficient to override this with an implementation that uses the instanceof operator.

Overrides:

equals in class java.lang.Object

Parameters:

o - an object to compare with this object.

Returns:

true iff the supplied object's class is the same as the class of this object.

hashCode

public final int hashCode()

Returns a hash code for this object.

Overrides:

hashCode in class java.lang.Object

Returns:

the hash code for the object.

isActive

public abstract boolean isActive()

Not currently used.

This is envisaged to be used if a protocol that is in use and needs to be removed sometime in the future. This will stop any further use of the protocol.

Returns:

boolean indicating whether protocol is active.

requiresUserInteraction

public abstract boolean requiresUserInteraction()

Returns whether the protocol requires user interaction in order for data to be delivered. There could be a protocol that writes data out to floppy disk or CD-R (see Tanenbaum's example of bandwidth and lorry!).

Returns:

boolean indicating whether user interaction is required.

getPosition

public final int getPosition()

Gets the position of this protocol in the order of preference.

Returns:

the order of preference as an int.

getLinkBuilder

protected abstract LinkFactory.Builder getLinkBuilder(java.util.Hashtable settings)

Obtains the Builder for this protocol. Provides a Hashtable that can can contain settings needed to construct the Link.

Parameters:

settings - Hashtable containing settings.

Returns:

the Builder for constructing Links.

startLinkServer

protected abstract LinkServer startLinkServer(NodeAddressID addressID)
                                       throws java.lang.IllegalArgumentException

Constructs, starts and returns a LinkServer on a specified NodeAddressID.

Parameters:

addressID - The address for the server to listen on.

Returns:

the constructed LinkServer

Throws:

java.lang.IllegalArgumentException - if the supplied NodeAddressID is invalid.

createAddressID

protected abstract NodeAddressID createAddressID(java.lang.String stAddressID,
                                                 boolean uniqueAddress)
                                          throws java.lang.IllegalArgumentException

Constructs a NodeAddressID from a String.

Parameters:

stAddressID - The address in String form.

uniqueAddress - boolean indicating whether address is unique.

Returns:

the constructed NodeAddressID

Throws:

java.lang.IllegalArgumentException - if the String supplied is invalid.