org.janusgraph.graphdb.internal

Class AbstractElement

java.lang.Object

org.janusgraph.graphdb.internal.AbstractElement

All Implemented Interfaces:

Comparable<JanusGraphElement>, org.apache.tinkerpop.gremlin.structure.Element, Idfiable, JanusGraphElement, InternalElement, Removable

Direct Known Subclasses:

AbstractTypedRelation, AbstractVertex

public abstract class AbstractElement
extends Object
implements InternalElement, Comparable<JanusGraphElement>

AbstractElement is the base class for all elements in JanusGraph. It is defined and uniquely identified by its id.

For the id, it holds that: id<0: Temporary id, will be assigned id>0 when the transaction is committed id=0: Virtual or implicit element that does not physically exist in the database id>0: Physically persisted element

Author:

Matthias Broecheler (me@matthiasb.com)

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.tinkerpop.gremlin.structure.Element

org.apache.tinkerpop.gremlin.structure.Element.Exceptions

Constructor Summary

Constructors

Constructor and Description
AbstractElement(Object id)

Method Summary

Modifier and Type	Method and Description
InternalVertex	clone()
static int	compare(JanusGraphElement e1, JanusGraphElement e2)
int	compareTo(JanusGraphElement other)
boolean	equals(Object other)
Object	getCompareId() Long identifier used to compare elements.
int	hashCode()
boolean	hasId() Checks whether this entity has a unique identifier.
Object	id() Returns a unique identifier for this entity.
boolean	isInvisible() Whether this element is invisible and should only be returned to queries that explicitly ask for invisible elements.
boolean	isLoaded() Checks whether this entity has been loaded into the current transaction and not yet modified.
boolean	isNew() Checks whether this entity has been newly created in the current transaction.
boolean	isRemoved() Checks whether this entity has been deleted into the current transaction.
static boolean	isTemporaryId(Object elementId)
void	setId(Object id)

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.janusgraph.graphdb.internal.InternalElement

getLifeCycle, graph, it, tx

Methods inherited from interface org.janusgraph.core.JanusGraphElement

property, remove, valueOrNull

Methods inherited from interface org.apache.tinkerpop.gremlin.structure.Element

keys, label, properties, property, value, values

Constructor Detail

AbstractElement

public AbstractElement(Object id)

Method Detail

isTemporaryId

public static boolean isTemporaryId(Object elementId)

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object other)

Overrides:

equals in class Object

compareTo

public int compareTo(JanusGraphElement other)

Specified by:

compareTo in interface Comparable<JanusGraphElement>

compare

public static int compare(JanusGraphElement e1,
                          JanusGraphElement e2)

clone

public InternalVertex clone()
                     throws CloneNotSupportedException

Overrides:

clone in class Object

Throws:

CloneNotSupportedException

getCompareId

public Object getCompareId()

Long identifier used to compare elements. Often, this is the same as id() but some instances of elements may be considered the same even if their ids differ. In that case, this method should be overwritten to return an id that can be used for comparison.

Specified by:

getCompareId in interface InternalElement

Returns:

id

public Object id()

Description copied from interface: JanusGraphElement

Returns a unique identifier for this entity.

The unique identifier may only be set when the transaction in which entity is created commits. Some entities are never assigned a unique identifier if they depend on a parent entity.

JanusGraph allocates blocks of identifiers and automatically assigns identifiers to elements automatically be default. This behavior can be partially overridden by setting GraphDatabaseConfiguration.ALLOW_SETTING_VERTEX_ID

Specified by:

id in interface org.apache.tinkerpop.gremlin.structure.Element

Specified by:

id in interface Idfiable

Specified by:

id in interface JanusGraphElement

Returns:

The unique identifier for this entity

See Also:

JanusGraphElement.hasId()

hasId

public boolean hasId()

Description copied from interface: JanusGraphElement

Checks whether this entity has a unique identifier.

Note that some entities may never be assigned an identifier and others will only be assigned an identifier at the end of a transaction.

Specified by:

hasId in interface JanusGraphElement

Returns:

true if this entity has been assigned a unique id, else false

setId

public void setId(Object id)

Specified by:

setId in interface InternalElement

isInvisible

public boolean isInvisible()

Description copied from interface: InternalElement

Whether this element is invisible and should only be returned to queries that explicitly ask for invisible elements.

Specified by:

isInvisible in interface InternalElement

Returns:

isNew

public boolean isNew()

Description copied from interface: JanusGraphElement

Checks whether this entity has been newly created in the current transaction.

Specified by:

isNew in interface JanusGraphElement

Returns:

True, if entity has been newly created, else false.

isLoaded

public boolean isLoaded()

Description copied from interface: JanusGraphElement

Checks whether this entity has been loaded into the current transaction and not yet modified.

Specified by:

isLoaded in interface JanusGraphElement

Returns:

True, has been loaded and not modified, else false.

isRemoved

public boolean isRemoved()

Description copied from interface: JanusGraphElement

Checks whether this entity has been deleted into the current transaction.

Specified by:

isRemoved in interface JanusGraphElement

Returns:

True, has been deleted, else false.