edu.nps.moves.dis
Class Pdu

java.lang.Object
  edu.nps.moves.dis.Pdu

All Implemented Interfaces:

java.io.Serializable

Direct Known Subclasses:

DistributedEmissionsFamilyPdu, EntityInformationFamilyPdu, EntityManagementFamilyPdu, LogisticsFamilyPdu, MinefieldFamilyPdu, RadioCommunicationsFamilyPdu, SimulationManagementFamilyPdu, SimulationManagementWithReliabilityFamilyPdu, SyntheticEnvironmentFamilyPdu, WarfareFamilyPdu

@Entity
public class Pdu
extends java.lang.Object
implements java.io.Serializable

The superclass for all PDUs. This incorporates the PduHeader record, section 5.2.29. Copyright (c) 2008-2010, MOVES Institute, Naval Postgraduate School. All rights reserved. This work is licensed under the BSD open source license, available at https://www.movesinstitute.org/licenses/bsd.html

Author:

DMcG

See Also:

Serialized Form

Field Summary

protected short	exerciseID Exercise ID
protected short	padding zero-filled array of padding
protected int	pduLength Length, in bytes, of the PDU.
protected short	pduType Type of pdu, unique for each PDU class
protected short	protocolFamily value that refers to the protocol family, eg SimulationManagement, et
protected short	protocolVersion The version of the protocol.
protected long	timestamp Timestamp value

Constructor Summary

Pdu()
Constructor

Method Summary

boolean	equals(java.lang.Object obj)
boolean	equalsImpl(java.lang.Object obj) Compare all fields that contribute to the state, ignoring transient and static fields, for this and the supplied object
short	getExerciseID()
int	getLength()
int	getMarshalledSize()
short	getPadding()
int	getPduLength()
short	getPduType()
edu.nps.moves.disenum.PduType	getPduTypeEnum() Returns the PduType, an enumeration from the disenum jar file.
long	getPk_Pdu() Primary key for hibernate, not part of the DIS standard
short	getProtocolFamily()
short	getProtocolVersion()
long	getTimestamp()
byte[]	marshal() A convenience method for marshalling to a byte array.
void	marshal(java.nio.ByteBuffer buff) Packs a Pdu into the ByteBuffer.
void	marshal(java.io.DataOutputStream dos)
byte[]	marshalWithDisAbsoluteTimestamp() A convieneince method to marshal to a byte array with the timestamp set to the DIS standard for absolute timestamps (which works only if the host is slaved to NTP).
void	marshalWithDisAbsoluteTimestamp(java.nio.ByteBuffer buff)
byte[]	marshalWithDisRelativeTimestamp() A convieneince method to marshal to a byte array with the timestamp set to the DIS standard for relative timestamps.
void	marshalWithDisRelativeTimestamp(java.nio.ByteBuffer buff)
byte[]	marshalWithNpsTimestamp() A convienience method to marshal a PDU using the NPS-specific format for timestamps, which is hundredths of a second since the start of the year.
void	marshalWithNpsTimestamp(java.nio.ByteBuffer buff)
byte[]	marshalWithUnixTimestamp() Another option for marshalling with the timestamp field set automatically.
void	marshalWithUnixTimestamp(java.nio.ByteBuffer buff)
long	readUnsignedInt(java.nio.ByteBuffer buff)
long	readUnsignedInt(java.io.DataInputStream dis)
void	setExerciseID(short pExerciseID)
void	setPadding(short pPadding)
void	setPduLength(int pPduLength)
void	setPduType(short pPduType)
void	setPk_Pdu(long pKeyName) Hibernate primary key, not part of the DIS standard
void	setProtocolFamily(short pProtocolFamily)
void	setProtocolVersion(short pProtocolVersion)
void	setTimestamp(long pTimestamp)
void	unmarshal(java.nio.ByteBuffer buff) Unpacks a Pdu from the underlying data.
void	unmarshal(java.io.DataInputStream dis)

Methods inherited from class java.lang.Object

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

Field Detail

protocolVersion

protected short protocolVersion

The version of the protocol. 5=DIS-1995, 6=DIS-1998.

exerciseID

protected short exerciseID

Exercise ID

pduType

protected short pduType

Type of pdu, unique for each PDU class

protocolFamily

protected short protocolFamily

value that refers to the protocol family, eg SimulationManagement, et

timestamp

protected long timestamp

Timestamp value

pduLength

protected int pduLength

Length, in bytes, of the PDU. Changed name from length to avoid use of Hibernate QL reserved word

padding

protected short padding

zero-filled array of padding

Constructor Detail

Pdu

public Pdu()

Constructor

Method Detail

getLength

public int getLength()

getMarshalledSize

public int getMarshalledSize()

getPk_Pdu

public long getPk_Pdu()

Primary key for hibernate, not part of the DIS standard

setPk_Pdu

public void setPk_Pdu(long pKeyName)

Hibernate primary key, not part of the DIS standard

setProtocolVersion

public void setProtocolVersion(short pProtocolVersion)

getProtocolVersion

public short getProtocolVersion()

setExerciseID

public void setExerciseID(short pExerciseID)

getExerciseID

public short getExerciseID()

setPduType

public void setPduType(short pPduType)

getPduType

public short getPduType()

getPduTypeEnum

public edu.nps.moves.disenum.PduType getPduTypeEnum()

Returns the PduType, an enumeration from the disenum jar file. This is an enumerated java type, rather than a simple short integer. This should NOT be marshalled to DIS or XML.

Returns:

this Pdu's type enumeration

setProtocolFamily

public void setProtocolFamily(short pProtocolFamily)

getProtocolFamily

public short getProtocolFamily()

setTimestamp

public void setTimestamp(long pTimestamp)

getTimestamp

public long getTimestamp()

setPduLength

public void setPduLength(int pPduLength)

getPduLength

public int getPduLength()

setPadding

public void setPadding(short pPadding)

getPadding

public short getPadding()

readUnsignedInt

public long readUnsignedInt(java.io.DataInputStream dis)

readUnsignedInt

public long readUnsignedInt(java.nio.ByteBuffer buff)

marshal

public void marshal(java.io.DataOutputStream dos)

unmarshal

public void unmarshal(java.io.DataInputStream dis)

marshal

public void marshal(java.nio.ByteBuffer buff)

Packs a Pdu into the ByteBuffer.

Parameters:

buff - The ByteBuffer at the position to begin writing

Throws:

java.nio.BufferOverflowException - if buff is too small

java.nio.ReadOnlyBufferException - if buff is read only

Since:

??

See Also:

ByteBuffer

unmarshal

public void unmarshal(java.nio.ByteBuffer buff)

Unpacks a Pdu from the underlying data.

Parameters:

buff - The ByteBuffer at the position to begin reading

Throws:

java.nio.BufferUnderflowException - if buff is too small

Since:

??

See Also:

ByteBuffer

marshal

public byte[] marshal()

A convenience method for marshalling to a byte array. This is not as efficient as reusing a ByteBuffer, but it is easy.

Returns:

a byte array with the marshalled Pdu

Since:

??

marshalWithDisAbsoluteTimestamp

public byte[] marshalWithDisAbsoluteTimestamp()

A convieneince method to marshal to a byte array with the timestamp set to the DIS standard for absolute timestamps (which works only if the host is slaved to NTP). This means the timestamp will roll over every hour.

Returns:

IEEE format byte array, with the timestamp set to the current DIS time

marshalWithDisAbsoluteTimestamp

public void marshalWithDisAbsoluteTimestamp(java.nio.ByteBuffer buff)

marshalWithDisRelativeTimestamp

public byte[] marshalWithDisRelativeTimestamp()

A convieneince method to marshal to a byte array with the timestamp set to the DIS standard for relative timestamps. The timestamp will roll over every hour

Returns:

IEEE format byte array, with the timestamp set to relative DIS time

marshalWithDisRelativeTimestamp

public void marshalWithDisRelativeTimestamp(java.nio.ByteBuffer buff)

marshalWithNpsTimestamp

public byte[] marshalWithNpsTimestamp()

A convienience method to marshal a PDU using the NPS-specific format for timestamps, which is hundredths of a second since the start of the year. This effectively eliminates the rollover issues from a practical standpoint.

Returns:

IEEE format byte array, with the timestamp set to hundredths of a second since the start of the year

marshalWithNpsTimestamp

public void marshalWithNpsTimestamp(java.nio.ByteBuffer buff)

marshalWithUnixTimestamp

public byte[] marshalWithUnixTimestamp()

Another option for marshalling with the timestamp field set automatically. The UNIX time is conventionally seconds since January 1, 1970. UTC time is used, and leap seconds are excluded. This approach is popular in the wild, but the time resolution is not very good for high frequency updates, such as aircraft. An entity updating at 30 PDUs/second would see 30 PDUs sent out with the same timestamp, and have 29 of them discarded as duplicate packets. Note that there are other "Unix times", such milliseconds since 1/1/1970, saved in a long. This cannot be used, since the value is saved in a long. Java's System.getCurrentTimeMillis() uses this value.

Returns:

IEEE format byte array, with the timetamp set to seconds since 1970

marshalWithUnixTimestamp

public void marshalWithUnixTimestamp(java.nio.ByteBuffer buff)

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object

equalsImpl

public boolean equalsImpl(java.lang.Object obj)

Compare all fields that contribute to the state, ignoring transient and static fields, for this and the supplied object

Parameters:

obj - the object to compare to

Returns:

true if the objects are equal, false otherwise.