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Class mil.navy.nps.dis.EntityID 

java.lang.Object
   |
   +----mil.navy.nps.dis.PduElement
           |
           +----mil.navy.nps.dis.EntityID
public class EntityID
extends PduElement
EntityID EntityID is a composite of several values that are commonly found together, and that,when combined, uniquely identify an entity in a simulation.

For a web-based reference, see

Note that I've "flattened" it a bit, by combining the simulation address record together with the entity ID in one object, rather than using the simulation address as its own object. This is a questionable move.

It's used in a variety of PDUs, typically to identify a receving and a sending entity. Since it uniquely identifies an entity in a virtual world, it's a good candidate to act as a hash table key.

HISTORY

15Nov96 DMcG New
10Mar97 DMcG cleaned up for javadoc

Version:
1.0
Author:
Don McGregor ( http://www.stl.nps.navy.mil/~mcgredo)

See Also:
ProtocolDataUnit, PduElement, SerializationInterface

Constructor Index

o EntityID()
o EntityID(short, short, short)

Method Index

o application()
o clone()
o deSerialize(DataInputStream)
o entity()
o equals(Object)
returns yes if the object is exactly equal to another object, ie, contains the same values.
o hashCode()
This provides a hash code for the object, since this is a handy way to uniquely identify entities.
o length()
o printValues(int)
o serialize(DataOutputStream)
o setApplication(int)
o setApplication(UnsignedShort)
o setEntity(int)
o setEntity(UnsignedShort)
o setSite(int)
o setSite(UnsignedShort)
o site()

Constructors

o EntityID 
  public EntityID()
o EntityID 
  public EntityID(short pSiteID,
                  short pApplicationID,
                  short pEntityID)

Methods

o clone 
  public Object clone()
Overrides:
clone in class PduElement
o serialize 
  public void serialize(DataOutputStream outputStream)
Overrides:
serialize in class PduElement
o deSerialize 
  public void deSerialize(DataInputStream inputStream)
Overrides:
deSerialize in class PduElement
o length 
  public int length()
Overrides:
length in class PduElement
o printValues 
  public void printValues(int indentLevel)
Overrides:
printValues in class PduElement
o hashCode 
  public int hashCode()
This provides a hash code for the object, since this is a handy way to uniquely identify entities. There's a problem, since there are 48 bits of information in the object, but the hash code has only 32 bits to put things in. The solution right now is to ignore the application ID when generating the hash code. Furthermore, the entity ID is in the upper 16 bits, while the site ID is in the lower 16 bits. The idea is that this will help spread out the hash code a bit more, since there are probably many more entities than sites, and putting the part with more information in the MSB helps spread things out.

Overrides:
hashCode in class Object
o equals 
  public boolean equals(Object obj)
returns yes if the object is exactly equal to another object, ie, contains the same values.

Overrides:
equals in class Object
o site 
  public UnsignedShort site()
o setSite 
  public void setSite(UnsignedShort pSite)
o setSite 
  public void setSite(int pSite)
o application 
  public UnsignedShort application()
o setApplication 
  public void setApplication(UnsignedShort pApplication)
o setApplication 
  public void setApplication(int pApplication)
o entity 
  public UnsignedShort entity()
o setEntity 
  public void setEntity(UnsignedShort pEntity)
o setEntity 
  public void setEntity(int pEntity)

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