com.uc3m.it.pfc.pdp
Class PDPMessage

java.lang.Object
  com.uc3m.it.pfc.pdp.PDPMessage

class PDPMessage

extends java.lang.Object

The PDPMessage class implements the mechanism to create, manage and parse all available PDP messages.

It provides mechanisms to create new messages from basic data types, convert it into byte arrays to adapt them to be sent through the network, and read an parse messages received from the network.

Version:

initial

Author:

Celeste Campo Vázquez (celeste[at]it.uc3m.es), José Carlos Perea Barreiro (jperea[at]it.uc3m.es)

Field Summary

private boolean	any "Any" message flag field.
private ServiceEntry[]	entry ServiceEntryList/PRList field form a PDP message
private byte	function_id Function ID header field
private static int	MAXIMUN_MESSAGE_LENGTH Maximun length in bytes for a PDP message
private static byte	MINIMUN_MESSAGE_LENGTH Minimun length in bytes for a PDP message
private boolean	overflow Overflow flag.
protected static byte	PDP_SERVICE_DEREGISTER Identifier for PDP ServiceDeregister messages
protected static byte	PDP_SERVICE_REPLY Identifier for PDP ServiceReply messages
protected static byte	PDP_SERVICE_REQUEST Identifier for PDP ServiceRequest messages
static byte	PDP_VERSION Version 1.0
private java.lang.String	service_type ServiceType field from a ServiceRequest message
private int	xid XID header field.

Constructor Summary

protected	PDPMessage(byte[] data) Constructor.
protected	PDPMessage(int xid, java.lang.String service_type, java.util.Vector pr_list, boolean any) Constructor.
protected	PDPMessage(int xid, java.util.Vector entry) Constructor.
private	PDPMessage(int xid, java.util.Vector entry, byte id) Private Constructor.
protected	PDPMessage(java.util.Vector entry) Constructor.

Method Summary

protected byte[]	getBytes() Translates this objecto into a byte array to send this PDP message through the network
private byte[]	getEntryBytes() Returns a byte array cotainning the information stored on the entry field
private byte	getFlags() Returns the flags header field form this PDP message
protected byte	getFunctionID() Returns the functionID header field of this PDP message.
protected ServiceEntry[]	getPrList() Returns the PRList field from a PDPServiceRequest message
protected ServiceEntry[]	getServiceEntry() Returns the ServiceEntry list within an array
protected java.lang.String	getServiceType() Returns the serviceType field from a PDPServiceRequest message
protected int	getXID() Returns the xid header field from the PDP message.
protected boolean	isAny() Returns whether the message is set as a 1-request 1-reply or not.
private void	newEntry(java.util.Vector v, int i) Fills entry field from the information given on the parameters
protected void	setXid(int xid) Sets the xid on this PDP message

Methods inherited from class java.lang.Object

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

Field Detail

PDP_VERSION

public static final byte PDP_VERSION

Version 1.0

See Also:

Constant Field Values

PDP_SERVICE_REQUEST

protected static final byte PDP_SERVICE_REQUEST

Identifier for PDP ServiceRequest messages

See Also:

Constant Field Values

PDP_SERVICE_REPLY

protected static final byte PDP_SERVICE_REPLY

Identifier for PDP ServiceReply messages

See Also:

Constant Field Values

PDP_SERVICE_DEREGISTER

protected static final byte PDP_SERVICE_DEREGISTER

Identifier for PDP ServiceDeregister messages

See Also:

Constant Field Values

MINIMUN_MESSAGE_LENGTH

private static final byte MINIMUN_MESSAGE_LENGTH

Minimun length in bytes for a PDP message

See Also:

Constant Field Values

MAXIMUN_MESSAGE_LENGTH

private static final int MAXIMUN_MESSAGE_LENGTH

Maximun length in bytes for a PDP message

See Also:

Constant Field Values

function_id

private byte function_id

Function ID header field

overflow

private boolean overflow

Overflow flag. true whether the entry message does not fit within one single datagram.

any

private boolean any

"Any" message flag field. When true it specifies a 1-request 1-reply type message

xid

private int xid

XID header field. Acts as a message request identifier

service_type

private java.lang.String service_type

ServiceType field from a ServiceRequest message

entry

private ServiceEntry[] entry

ServiceEntryList/PRList field form a PDP message

Constructor Detail

PDPMessage

protected PDPMessage(int xid,
                     java.lang.String service_type,
                     java.util.Vector pr_list,
                     boolean any)
              throws PDPException

Constructor. This method creates a new PDP ServiceRequest message with the information given on the parameters

Parameters:

xid - XID message field that identifies every ServiceRequest message

service_type - Type of service to discover on the network

pr_list - Vector of already known services of the type of service requested on the message

any - Any flag field that identifies tye type of the request sent to the network. When true this request is a 1-request 1-reply message type

PDPMessage

protected PDPMessage(int xid,
                     java.util.Vector entry)
              throws PDPException

Constructor. Creates a new ServiceReply message with the information given on the parameters. This method internaly uses ( int, Vector, byte ) Constructor.

Parameters:

xid - XID message field that identifies every ServiceReply message

entry - Vector of services stored on the message

PDPMessage

protected PDPMessage(java.util.Vector entry)
              throws PDPException

Constructor. Creates a new ServiceDeregister message with the information given on the parameter. This method internaly uses ( Vector ) Constructor.

Parameters:

entry - Vector of services stored on the message

PDPMessage

private PDPMessage(int xid,
                   java.util.Vector entry,
                   byte id)
            throws PDPException

Private Constructor. Creates a new ServiceReply (see ( int, Vector )) or ServiceDeregister (see ( Vector )) message to be sent throgh the network.

Parameters:

xid - XID message field that identifies every ServiceReply message. On a ServiceDeregister message this field is set to 0x00

entry - Vector of services stored on the message

id - FunctionID header field message

PDPMessage

protected PDPMessage(byte[] data)
              throws PDPException

Constructor. Creates a new PDPMessage object from a message received from the network.

Parameters:

data - Byte array with the message received from the network

Method Detail

isAny

protected boolean isAny()

Returns whether the message is set as a 1-request 1-reply or not.

Returns:

The "ANY" message flag field

getServiceEntry

protected ServiceEntry[] getServiceEntry()

Returns the ServiceEntry list within an array

Returns:

The serviceentry message field from a ServiceReply or ServiceDeregister message

getFunctionID

protected byte getFunctionID()

Returns the functionID header field of this PDP message.

Returns:

FunctionID header field

getPrList

protected ServiceEntry[] getPrList()

Returns the PRList field from a PDPServiceRequest message

Returns:

PRList message field from a ServiceRequest message

getServiceType

protected java.lang.String getServiceType()

Returns the serviceType field from a PDPServiceRequest message

Returns:

ServiceType message field from a ServiceRequest message

getXID

protected int getXID()

Returns the xid header field from the PDP message.

Returns:

XID header field

setXid

protected void setXid(int xid)

Sets the xid on this PDP message

Parameters:

xid - The xid to set

getFlags

private byte getFlags()

Returns the flags header field form this PDP message

Returns:

The flags header field

getBytes

protected byte[] getBytes()

Translates this objecto into a byte array to send this PDP message through the network

newEntry

private void newEntry(java.util.Vector v,
                      int i)

Fills entry field from the information given on the parameters

Parameters:

v - Vector of ServiceEntry objects to add on the entry field

i - number of elements of the vector to add on the entry field

getEntryBytes

private byte[] getEntryBytes()

Returns a byte array cotainning the information stored on the entry field

Returns:

The byte array with the ServiceEntry message information