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An open source implementation of the Distributed Interactive Simulation (DIS) IEEE-1278 protocol
package edu.nps.moves.dis;
import java.util.*;
import java.io.*;
import edu.nps.moves.disenum.*;
import edu.nps.moves.disutil.*;
// Jaxb and Hibernate annotations generally won't work on mobile devices. XML serialization uses jaxb, and
// javax.persistence uses the JPA JSR, aka hibernate. See the Hibernate site for details.
// To generate Java code without these, and without the annotations scattered through the
// see the XMLPG java code generator, and set the boolean useHibernateAnnotations and useJaxbAnnotions
// to false, and then regenerate the code
import javax.xml.bind.*; // Used for JAXB XML serialization
import javax.xml.bind.annotation.*; // Used for XML serialization annotations (the @ stuff)
import javax.persistence.*; // Used for JPA/Hibernate SQL persistence
/**
* Each entity in a given DIS simulation application shall be given an entity identifier number unique to all other entities in that application. This identifier number is valid for the duration of the exercise; however, entity identifier numbers may be reused when all possible numbers have been exhausted. No entity shall have an entity identifier number of NO_ENTITY, ALL_ENTITIES, or RQST_ASSIGN_ID. The entity iden- tifier number need not be registered or retained for future exercises. The entity identifier number shall be specified by a 16-bit unsigned integer. An entity identifier number equal to zero with valid site and application identification shall address a simulation application. An entity identifier number equal to ALL_ENTITIES shall mean all entities within the specified site and application. An entity identifier number equal to RQST_ASSIGN_ID allows the receiver of the create entity to define the entity identifier number of the new entity.
*
* 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
*/
@Entity // Hibernate
@Inheritance(strategy=InheritanceType.JOINED) // Hibernate
public class EntityID extends Object implements Serializable
{
/** Primary key for hibernate, not part of the DIS standard */
private long pk_EntityID;
/** The site ID */
protected int site;
/** The application ID */
protected int application;
/** the entity ID */
protected int entity;
/** Constructor */
public EntityID()
{
}
@Transient // Marked as transient to prevent hibernate from thinking this is a persistent property
public int getMarshalledSize()
{
int marshalSize = 0;
marshalSize = marshalSize + 2; // site
marshalSize = marshalSize + 2; // application
marshalSize = marshalSize + 2; // entity
return marshalSize;
}
/** Primary key for hibernate, not part of the DIS standard */
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
public long getPk_EntityID()
{
return pk_EntityID;
}
/** Hibernate primary key, not part of the DIS standard */
public void setPk_EntityID(long pKeyName)
{
this.pk_EntityID = pKeyName;
}
public void setSite(int pSite)
{ site = pSite;
}
@XmlAttribute // Jaxb
@Basic // Hibernate
public int getSite()
{ return site;
}
public void setApplication(int pApplication)
{ application = pApplication;
}
@XmlAttribute // Jaxb
@Basic // Hibernate
public int getApplication()
{ return application;
}
public void setEntity(int pEntity)
{ entity = pEntity;
}
@XmlAttribute // Jaxb
@Basic // Hibernate
public int getEntity()
{ return entity;
}
public void marshal(DataOutputStream dos)
{
try
{
dos.writeShort( (short)site);
dos.writeShort( (short)application);
dos.writeShort( (short)entity);
} // end try
catch(Exception e)
{
System.out.println(e);}
} // end of marshal method
public void unmarshal(DataInputStream dis)
{
try
{
site = (int)dis.readUnsignedShort();
application = (int)dis.readUnsignedShort();
entity = (int)dis.readUnsignedShort();
} // end try
catch(Exception e)
{
System.out.println(e);
}
} // end of unmarshal method
/**
* Packs a Pdu into the ByteBuffer.
* @throws java.nio.BufferOverflowException if buff is too small
* @throws java.nio.ReadOnlyBufferException if buff is read only
* @see java.nio.ByteBuffer
* @param buff The ByteBuffer at the position to begin writing
* @since ??
*/
public void marshal(java.nio.ByteBuffer buff)
{
buff.putShort( (short)site);
buff.putShort( (short)application);
buff.putShort( (short)entity);
} // end of marshal method
/**
* Unpacks a Pdu from the underlying data.
* @throws java.nio.BufferUnderflowException if buff is too small
* @see java.nio.ByteBuffer
* @param buff The ByteBuffer at the position to begin reading
* @since ??
*/
public void unmarshal(java.nio.ByteBuffer buff)
{
site = (int)(buff.getShort() & 0xFFFF);
application = (int)(buff.getShort() & 0xFFFF);
entity = (int)(buff.getShort() & 0xFFFF);
} // end of unmarshal method
/*
* The equals method doesn't always work--mostly it works only on classes that consist only of primitives. Be careful.
*/
@Override
public boolean equals(Object obj)
{
if(this == obj){
return true;
}
if(obj == null){
return false;
}
if(getClass() != obj.getClass())
return false;
return equalsImpl(obj);
}
/**
* Compare all fields that contribute to the state, ignoring
transient and static fields, for this and the supplied object
* @param obj the object to compare to
* @return true if the objects are equal, false otherwise.
*/
public boolean equalsImpl(Object obj)
{
boolean ivarsEqual = true;
if(!(obj instanceof EntityID))
return false;
final EntityID rhs = (EntityID)obj;
if( ! (site == rhs.site)) ivarsEqual = false;
if( ! (application == rhs.application)) ivarsEqual = false;
if( ! (entity == rhs.entity)) ivarsEqual = false;
return ivarsEqual;
}
/**
* Override of base class hashCode. This is convienent to use when looking up entities in
* a hash table. It uses the application and entity IDs to fill out the 32 bits. The idea
* is to get a "pretty close" to unique hashcode for each entity ID in 32 bits, and the
* best way to do that is leave out the site ID while keeping the rest, which tends to
* be more unique.
*/
@Override
public int hashCode()
{
int hashcode = application;
hashcode = hashcode << 16;
hashcode = hashcode + entity;
return hashcode;
}
} // end of class