com.franz.ag
Class Node

java.lang.Object
  com.franz.ag.ValueObject
      com.franz.ag.ValueNode
          com.franz.ag.ResourceNode
              com.franz.ag.Node

All Implemented Interfaces:

java.lang.Comparable, Resource, java.io.Serializable, URI, Value

public class Node

extends ResourceNode

implements URI

This class represents an instance of a labelled resource node in AllegroGraph.

The AllegroGraph object defines two slots, id and uri. Both slots are copied to the Java instance.

The URI member may be a lazy value in the Java instance. If queryURI returns null, getURI() will need a round-trip to the triple store to fetch the actual value.

There is no public constructor. Node instances are created by calls to AllegroGraph methods.

See Also:

Serialized Form

Field Summary

static Node

nullContext

Method Summary

void	add() Add this node to the AllegroGraph triple store.
boolean	equals(java.lang.Object other) Implement equality for Node instances.
UPI	getAGId() Retrieve the AllegroGraph ID number of the Node.
java.lang.String	getLocalName() Retrieve the local name component of the URI string associated with the node instance.
java.lang.String	getNamespace() Retrieve the namespace component of the URI string associated with the node instance.
StatementIterator	getPredicateStatements() Gets all statements from the RDF graph for which this URI is the predicate.
java.lang.String	getURI() Returns the String-representation of this URI.
int	hashCode() Compute the hashcode of a Node instance.
java.lang.String	queryURI() Retrieve the URI string associated with the node instance.
java.lang.String	toString() Retrieve the URI string associated with the node instance.

Methods inherited from class com.franz.ag.ResourceNode

addProperty, getSubjectStatements

Methods inherited from class com.franz.ag.ValueNode

compareTo, getObjectStatements, queryAGId

Methods inherited from class com.franz.ag.ValueObject

compareTo

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.openrdf.model.Resource

addProperty, getSubjectStatements

Methods inherited from interface org.openrdf.model.Value

getObjectStatements

Methods inherited from interface java.lang.Comparable

compareTo

Field Detail

nullContext

public static final Node nullContext

Method Detail

getAGId

public UPI getAGId()
            throws AllegroGraphException

Retrieve the AllegroGraph ID number of the Node.

Returns:

the ID number

If the Node is already registered in the AG triple store, return the locally cached value of the ID number. Otherwise, register the Node in the AG triple store and return the new ID number.

Throws:

AllegroGraphException

queryURI

public java.lang.String queryURI()

Retrieve the URI string associated with the node instance.

Returns:

A string or null. If the returned value is null, the actual value must be obtained by calling getURI().

getLocalName

public java.lang.String getLocalName()

Retrieve the local name component of the URI string associated with the node instance.

Specified by:

getLocalName in interface URI

Returns:

A string. If the value is not in the Java cache, retrieve it from the triple store.

getNamespace

public java.lang.String getNamespace()

Retrieve the namespace component of the URI string associated with the node instance.

Specified by:

getNamespace in interface URI

Returns:

A string or null if the URI does not have a namespace component. If the value is not in the Java cache, retrieve it from the triple store.

toString

public java.lang.String toString()

Retrieve the URI string associated with the node instance.

Returns:

A string. If the value is not in the Java cache, retrieve it from the triple store.

Defined in interface org.openrdf.model.URI

equals

public boolean equals(java.lang.Object other)

Implement equality for Node instances.

Two Node instances are equal if both are registered in the AllegroGraph triple store and they have identical AllegroGraph part id numbers.

Otherwise, the string representations are compared.

hashCode

public int hashCode()

Compute the hashcode of a Node instance.

The hashcode of a Node instance is the hashcode of its string representation.

getPredicateStatements

public StatementIterator getPredicateStatements()
                                         throws GraphException

Description copied from interface: URI

Gets all statements from the RDF graph for which this URI is the predicate.

Specified by:

getPredicateStatements in interface URI

Throws:

GraphException

getURI

public java.lang.String getURI()

Description copied from interface: URI

Returns the String-representation of this URI. The String-representation consists of the concatenation of the namespace and the local name.

Specified by:

getURI in interface URI

Returns:

The String-representation of this URI.

add

public void add()
         throws AllegroGraphException

Add this node to the AllegroGraph triple store. If the node already is in the triple store, do nothing.

A Node instance is in the triple store if queryAGId() returns a non-negative value.

Throws:

AllegroGraphException