nz.ac.waikato.mcennis.rat.graph
Class DerbyGraph

java.lang.Object
  nz.ac.waikato.mcennis.rat.graph.model.ModelShell
      nz.ac.waikato.mcennis.rat.graph.DerbyGraph

All Implemented Interfaces:

java.io.Serializable, Graph, Listener, Model, ParsedObject

Direct Known Subclasses:

PostgresqlGraph

public class DerbyGraph
extends ModelShell
implements Graph, Listener

Class that implements all the JDBC code for a Derby backed graph model. This model differs from persistance in that all loading of actors, links, and properties is done using lazy techniques (they are not createde until requested). Provided that the appropriate actor class (DBActor by default) is used, persistance is maintained with generated references in a manner similar to hibernate.

The first time this system is utilized, it requires initialization to create the appropriate tables in the database. This database must be the same for the corresponding actor class, but is handled by default (unless the class is changed between startup and actor request.)

The system requires two paramters - the directory of the database and the database name. All JDBC calls are compiled and have auto-commit disabled. Periodic calls to commit() are required to maintain consistancy between the database and memory-resident components.

See Also:

Serialized Form

Nested Class Summary

class

DerbyGraph.ActorIterator

Field Summary

static long

serialVersionUID

Fields inherited from class nz.ac.waikato.mcennis.rat.graph.model.ModelShell

listener

Constructor Summary

DerbyGraph()
Creates a new instance of DerbyGraph

Method Summary

void	add(Actor u) Add a user to the graph.
void	add(Graph g) Add a graph (g) to the graph.
void	add(Link link) Adds a userlink to the graph.
void	add(PathSet pathSet) Add a PathSet to this graph.
void	add(Property prop) Add a property to this graph.
void	addChild(Graph g) FIXME: Does not save to database
void	anonymize() Replaces all actor IDs with an anonymous numeric ID.
void	clear() Removes all data from the database.
void	close() Attempts to release all resources created by the startup method
void	commit() Commit the contents to database or storage.
void	deleteDatabase() Attempts to remove the database tables so that initializeDatabase will be needed to utilize the graph again.
protected void	finalize()
Actor[]	getActor() Retrieve an array of all actors of all types.
Actor[]	getActor(java.lang.String type) Retrieve an array of all actors of a given type.
Actor	getActor(java.lang.String type, java.lang.String ID) Retrieve the users that has the given ID.
protected java.lang.String	getActorClass() Determine what class will be used for the creation of actor objects.
int	getActorCount(java.lang.String mode) Returns the number of actors of the given type
java.util.Iterator<Actor>	getActorIterator(java.lang.String type) Create a read only iterator over all actors.
java.lang.String[]	getActorTypes() List all types - returns null if no actors exist.
Graph[]	getChildren() FIXME: Does not properly access database
Graph	getChildren(java.lang.String id) FIXME: Does not properly access database
java.io.File	getDirectory() Return the directory that this object will or is using.
Graph[]	getGraphs(java.util.regex.Pattern pattern) FIXME: does not return graphs properly
java.lang.String	getID() Return the ID associated with this Graph
Link[]	getLink() Return all user to user links in this graph in an array.
Link[]	getLink(java.lang.String type) Retrieve an array of all userlinks of the given type from this graph or null if no such links are in this graph.
Link[]	getLink(java.lang.String type, Actor sourceActor, Actor destActor) Returns all links of the given type (relation) type going from actor sourceActor to actor destActor or null.
Link[]	getLinkByDestination(java.lang.String type, Actor destActor) Returns all links (edges, arcs) of type (relation) type that point to the given actor.
Link[]	getLinkBySource(java.lang.String type, Actor sourceActor) Returns all links (edges, arcs) of type (relation) type that go from the given actor to any destination.
java.lang.String[]	getLinkTypes() Returns all link types currently in this graph or null if no links are present.
Parameter[]	getParameters() Obtain a computer-readable description of the parameters and options this graph supports
Graph	getParent() FIXME: Does not properly access database
PathSet[]	getPathSet() Return all PathSets associated with this graph.
PathSet	getPathSet(java.lang.String id) Return the named PathSet.
Property[]	getProperty() Returns an array of all properties associated with this object or null if none exist
Property	getProperty(java.lang.String type) Return a property named by the given string or null if no property by this name exists
Graph	getSubGraph(java.util.Properties props, java.util.Set<Actor> actor) FIXME: write subgraph code for Derby Graph
Graph[]	getSubGraph(Query q) Return newly created subgraphs that matches the given query FIXME: Currently not implemented in any graph.
void	init(java.util.Properties map) Set the parameters of this graph from the following property object.
protected void	initActor() Performs initialization of the DBActor class - a static call that prepares all subsequent calls for actor creation.
void	initializeDatabase() The first call to be made if the database has never been used before.
boolean	isInitialized() Determine if 'startup' has been called for this graph.
protected void	prepareStatement() Prepares all statements utilized by DerbyGraph.
void	publishChange(Model m, int type, int argument) Records changes in properties of this graph, updating the database as needed.
void	remove(Actor u) Identifies the given user and removes it and all links involving it from the graph.
void	remove(Link ul) remove all user links with the same type, user ID, and artist ID from the graph
protected Actor	retrieveActor(int id) Retrieve an actor object from the database with its database's numeric id.
protected void	setActorClass(java.lang.String actorClass) Determine what class will be used for the creation of actor objects.
protected Property[]	setActorProperties(int a) Aquire a set of properties from the database attached to a given actor.
void	setDirectory(java.io.File f) Set the directory that DerbyGraph will look for its database
void	setID(java.lang.String id) Set this graph's ID to this value.
void	setSubGraph(Query q) Same as getSubGraph but the resulting graphs are stored internally NOTE: this interface may be removed.
void	startup() Starts the database Creates a database connection at the directory 'directory' with database name 'database' aquires the graph id of the root graph compiles all the prepared statements used in the class

Methods inherited from class nz.ac.waikato.mcennis.rat.graph.model.ModelShell

addListener, fireChange

Methods inherited from class java.lang.Object

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

Methods inherited from interface nz.ac.waikato.mcennis.rat.graph.model.Model

addListener

Field Detail

serialVersionUID

public static final long serialVersionUID

See Also:

Constant Field Values

Constructor Detail

DerbyGraph

public DerbyGraph()

Creates a new instance of DerbyGraph

Method Detail

startup

public void startup()
             throws java.sql.SQLException

Starts the database

• Creates a database connection at the directory 'directory' with database name 'database'
• aquires the graph id of the root graph
• compiles all the prepared statements used in the class

  Throws:

  java.sql.SQLException

initActor

protected void initActor()

Performs initialization of the DBActor class - a static call that prepares all subsequent calls for actor creation.

See Also:

DBActor

prepareStatement

protected void prepareStatement()
                         throws java.sql.SQLException

Prepares all statements utilized by DerbyGraph.

Throws:

java.sql.SQLException

initializeDatabase

public void initializeDatabase()
                        throws java.sql.SQLException

The first call to be made if the database has never been used before. It creates its own connection, so startup is not needed before. If called on an already generated table, the system will report errors, but not damage the table. Also closes its own connection, so close is not needed either.

Throws:

java.sql.SQLException

finalize

protected void finalize()
                 throws java.lang.Throwable

Overrides:

finalize in class java.lang.Object

Throws:

java.lang.Throwable

close

public void close()

Attempts to release all resources created by the startup method

Specified by:

close in interface Graph

isInitialized

public boolean isInitialized()

Determine if 'startup' has been called for this graph.

Returns:

whether or not this graph has been initialized

clear

public void clear()

Removes all data from the database. Assumes that startup has been called.

deleteDatabase

public void deleteDatabase()

Attempts to remove the database tables so that initializeDatabase will be needed to utilize the graph again.

add

public void add(Actor u)

Description copied from interface: Graph

Add a user to the graph. This replaces the user if a user with the same ID already exists.

Specified by:

add in interface Graph

Parameters:

u - user to be included in the graph.

add

public void add(Link link)

Description copied from interface: Graph

Adds a userlink to the graph. There is no limit on the number of links between users or even with the same type, source user, and destination user.

Specified by:

add in interface Graph

Parameters:

link - description of a named link between two users

remove

public void remove(Actor u)

Description copied from interface: Graph

Identifies the given user and removes it and all links involving it from the graph.

Specified by:

remove in interface Graph

Parameters:

u - user to be removed from the graph.

remove

public void remove(Link ul)

Description copied from interface: Graph

remove all user links with the same type, user ID, and artist ID from the graph

Specified by:

remove in interface Graph

Parameters:

ul - link to be removed from the graph.

getActor

public Actor getActor(java.lang.String type,
                      java.lang.String ID)

Description copied from interface: Graph

Retrieve the users that has the given ID. Returns null if no user is in the graph with that ID.

Specified by:

getActor in interface Graph

ID - ID string identifying an user

Returns:

user object who has this ID or null if it is not present

getActor

public Actor[] getActor()

Description copied from interface: Graph

Retrieve an array of all actors of all types. Returns null if no actors are in the graph.

Specified by:

getActor in interface Graph

Returns:

array of all users in the graph

getActor

public Actor[] getActor(java.lang.String type)

Description copied from interface: Graph

Retrieve an array of all actors of a given type. Returns null if there are no actors of that type in the graph.

Specified by:

getActor in interface Graph

Parameters:

type - class of actor to return

Returns:

array of actors of the given type

getActorIterator

public java.util.Iterator<Actor> getActorIterator(java.lang.String type)

Description copied from interface: Graph

Create a read only iterator over all actors.

Specified by:

getActorIterator in interface Graph

Parameters:

type - type (mode) of actor to return

Returns:

iterator over all actors of the given type

getActorTypes

public java.lang.String[] getActorTypes()

Description copied from interface: Graph

List all types - returns null if no actors exist.

Specified by:

getActorTypes in interface Graph

Returns:

array of all type names in this graph

getLink

public Link[] getLink()

Description copied from interface: Graph

Return all user to user links in this graph in an array. Returns null if no such user link exists.

Specified by:

getLink in interface Graph

Returns:

array of all userlinks or null

retrieveActor

protected Actor retrieveActor(int id)

Retrieve an actor object from the database with its database's numeric id. Returns null if no such actor exists.

Parameters:

id - numeric id of this object

Returns:

Actor object this id refers to

getLink

public Link[] getLink(java.lang.String type)

Description copied from interface: Graph

Retrieve an array of all userlinks of the given type from this graph or null if no such links are in this graph.

Specified by:

getLink in interface Graph

Returns:

array of all user links of a given type or null

getLinkBySource

public Link[] getLinkBySource(java.lang.String type,
                              Actor sourceActor)

Description copied from interface: Graph

Returns all links (edges, arcs) of type (relation) type that go from the given actor to any destination. Returns null if no such links exist.

Specified by:

getLinkBySource in interface Graph

Parameters:

type - type (relation) of link to return

sourceActor - starting point of the link

Returns:

Array of links or null

getLinkByDestination

public Link[] getLinkByDestination(java.lang.String type,
                                   Actor destActor)

Description copied from interface: Graph

Returns all links (edges, arcs) of type (relation) type that point to the given actor. Returns null if no such links exist

Specified by:

getLinkByDestination in interface Graph

Parameters:

type - type (relation) of link to return

destActor - actor pointed to by links

Returns:

Array of links or null

getLink

public Link[] getLink(java.lang.String type,
                      Actor sourceActor,
                      Actor destActor)

Description copied from interface: Graph

Returns all links of the given type (relation) type going from actor sourceActor to actor destActor or null. This is typically 1 link or null, but the spec does not forbid multiple links of the same type (relation) between two actors.

Specified by:

getLink in interface Graph

Parameters:

type - type (relation) of the link to return

sourceActor - starting point of the link

destActor - actor pointed to by links

Returns:

Array of links or null

getLinkTypes

public java.lang.String[] getLinkTypes()

Description copied from interface: Graph

Returns all link types currently in this graph or null if no links are present.

Specified by:

getLinkTypes in interface Graph

Returns:

array of link types

getSubGraph

public Graph[] getSubGraph(Query q)

Description copied from interface: Graph

Return newly created subgraphs that matches the given query FIXME: Currently not implemented in any graph. FIXME: Query structure needs to be defined.

Specified by:

getSubGraph in interface Graph

Parameters:

q - query object to be executed.

Returns:

Array of graphs created by the query or null if none are created

setSubGraph

public void setSubGraph(Query q)

Description copied from interface: Graph

Same as getSubGraph but the resulting graphs are stored internally NOTE: this interface may be removed.

Specified by:

setSubGraph in interface Graph

Parameters:

q - Query to be executed

getProperty

public Property[] getProperty()

Description copied from interface: Graph

Returns an array of all properties associated with this object or null if none exist

Specified by:

getProperty in interface Graph

Returns:

Array of properties

getProperty

public Property getProperty(java.lang.String type)

Description copied from interface: Graph

Return a property named by the given string or null if no property by this name exists

Specified by:

getProperty in interface Graph

Parameters:

type - property's name

Returns:

Given property

add

public void add(Property prop)
         throws java.lang.NullPointerException

Description copied from interface: Graph

Add a property to this graph. If a property by this name already exists, it is overwritten with the given property.

Specified by:

add in interface Graph

Parameters:

prop - property to be added.

Throws:

java.lang.NullPointerException

getPathSet

public PathSet[] getPathSet()

Description copied from interface: Graph

Return all PathSets associated with this graph. Null if no PathSets are in the current graph.

Specified by:

getPathSet in interface Graph

Returns:

Array of PathSets

getPathSet

public PathSet getPathSet(java.lang.String id)

Description copied from interface: Graph

Return the named PathSet. Returns null if no PathSet of the given ID exists.

Specified by:

getPathSet in interface Graph

Parameters:

id - ID of the PathSet to return

Returns:

PathSet specified by this ID

add

public void add(PathSet pathSet)

Description copied from interface: Graph

Add a PathSet to this graph. If another PathSet of the same ID exists, it will be overwritten.

Specified by:

add in interface Graph

Parameters:

pathSet - PathSet to be added to this graph

setID

public void setID(java.lang.String id)

Description copied from interface: Graph

Set this graph's ID to this value. Graph ID's must be unique.

Specified by:

setID in interface Graph

Parameters:

id - graph ID

getID

public java.lang.String getID()

Description copied from interface: Graph

Return the ID associated with this Graph

Specified by:

getID in interface Graph

Returns:

ID

setDirectory

public void setDirectory(java.io.File f)

Set the directory that DerbyGraph will look for its database

Parameters:

f - file representing the target directory.

getDirectory

public java.io.File getDirectory()

Return the directory that this object will or is using.

Returns:

directory object

setActorProperties

protected Property[] setActorProperties(int a)
                                 throws java.sql.SQLException

Aquire a set of properties from the database attached to a given actor. Returns a zero length array if no properties exist for this actor.

Parameters:

a - unique id of the actor whose properties are to be retrieved

Returns:

set of properties attached to given actor

Throws:

java.sql.SQLException

commit

public void commit()

Description copied from interface: Graph

Commit the contents to database or storage. This is a null operation for memory only objects. (Delaying committing changes to be in batches can result in a massive decrease in execution time.)

Specified by:

commit in interface Graph

add

public void add(Graph g)

Description copied from interface: Graph

Add a graph (g) to the graph. Will be changed to be a graph helper - deprecated by addChild(Graph g)

Specified by:

add in interface Graph

Parameters:

g - graph to be added

anonymize

public void anonymize()

Description copied from interface: Graph

Replaces all actor IDs with an anonymous numeric ID.

Specified by:

anonymize in interface Graph

publishChange

public void publishChange(Model m,
                          int type,
                          int argument)

Records changes in properties of this graph, updating the database as needed.

Specified by:

publishChange in interface Listener

Parameters:

m - property that is modified

type - currently only records adding a property

getParent

public Graph getParent()

FIXME: Does not properly access database

Specified by:

getParent in interface Graph

Returns:

parent graph

getChildren

public Graph[] getChildren()

FIXME: Does not properly access database

Specified by:

getChildren in interface Graph

Returns:

Array of graphs that are children of this graph

getChildren

public Graph getChildren(java.lang.String id)

FIXME: Does not properly access database

Specified by:

getChildren in interface Graph

Parameters:

id - ID of the graph to return

Returns:

Graph with the given ID

addChild

public void addChild(Graph g)

FIXME: Does not save to database

Specified by:

addChild in interface Graph

Parameters:

g - Child Graph

getGraphs

public Graph[] getGraphs(java.util.regex.Pattern pattern)

FIXME: does not return graphs properly

Specified by:

getGraphs in interface Graph

Parameters:

pattern -

Returns:

setActorClass

protected void setActorClass(java.lang.String actorClass)

Determine what class will be used for the creation of actor objects.

Parameters:

actorClass - name of class of actor

See Also:

ActorFactory

getActorClass

protected java.lang.String getActorClass()

Determine what class will be used for the creation of actor objects.

Returns:

String used to create actors in ActorFactory

See Also:

ActorFactory

getSubGraph

public Graph getSubGraph(java.util.Properties props,
                         java.util.Set<Actor> actor)
                  throws java.lang.Exception

FIXME: write subgraph code for Derby Graph

Specified by:

getSubGraph in interface Graph

Parameters:

props - Properties for creating a new Graph

actor - subset of graph's actors to make the subgraph from

Returns:

child graph of this graph

Throws:

java.lang.Exception - if actor is null or properties is null

getParameters

public Parameter[] getParameters()

Description copied from interface: Graph

Obtain a computer-readable description of the parameters and options this graph supports

Specified by:

getParameters in interface Graph

Returns:

Description of all parameters this graph object supports.

init

public void init(java.util.Properties map)

Description copied from interface: Graph

Set the parameters of this graph from the following property object.

Specified by:

init in interface Graph

Parameters:

map - properties to be set

getActorCount

public int getActorCount(java.lang.String mode)

Description copied from interface: Graph

Returns the number of actors of the given type

Specified by:

getActorCount in interface Graph

Parameters:

mode - type of actor to query

Returns:

int number of actors of the given type