org.janusgraph.core

Interface EdgeLabel

All Superinterfaces:

org.apache.tinkerpop.gremlin.structure.Element, org.apache.tinkerpop.gremlin.structure.util.Host, Idfiable, JanusGraphElement, JanusGraphSchemaElement, JanusGraphSchemaType, JanusGraphVertex, Namifiable, RelationType, Removable, org.apache.tinkerpop.gremlin.structure.Vertex

All Known Implementing Classes:

BaseLabel, EdgeLabelVertex

public interface EdgeLabel
extends RelationType

EdgeLabel is an extension of RelationType for edges. Each edge in JanusGraph has a label.

An edge label defines the following characteristics of an edge:

• Directionality: An edge is either directed or unidirected. A directed edge can be thought of as a "normal" edge: it points from one vertex to another and both vertices are aware of the edge's existence. Hence the edge can be traversed in both directions. A unidirected edge is like a hyperlink in that only the out-going vertex is aware of its existence and it can only be traversed in the outgoing direction.
• Multiplicity: The multiplicity of an edge imposes restrictions on the number of edges for a particular label that are allowed on a vertex. This allows the definition and enforcement of domain constraints.

Author:

Matthias Bröcheler (me@matthiasb.com)

See Also:

RelationType

Nested Class Summary

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

org.apache.tinkerpop.gremlin.structure.Vertex.Exceptions

Field Summary

Fields inherited from interface org.apache.tinkerpop.gremlin.structure.Vertex

DEFAULT_LABEL, EMPTY_ARGS

Method Summary

Modifier and Type	Method and Description
boolean	isDirected() Checks whether this labels is defined as directed.
boolean	isUnidirected() Checks whether this labels is defined as unidirected.
Collection<Connection>	mappedConnections() Collects all connection constraints.
Collection<PropertyKey>	mappedProperties() Collects all property constraints.
Multiplicity	multiplicity() The Multiplicity for this edge label.

Methods inherited from interface org.janusgraph.core.RelationType

isEdgeLabel, isPropertyKey

Methods inherited from interface org.janusgraph.core.JanusGraphVertex

addEdge, isModified, label, property, property, property, query, vertexLabel

Methods inherited from interface org.janusgraph.core.JanusGraphElement

graph, hasId, id, isLoaded, isNew, isRemoved, remove, valueOrNull

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

edges, properties, property, vertices

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

keys, value, values

Methods inherited from interface org.apache.tinkerpop.gremlin.structure.util.Host

getHostingVertex

Methods inherited from interface org.janusgraph.core.schema.JanusGraphSchemaType

isNew, longId

Methods inherited from interface org.janusgraph.core.Namifiable

name

Method Detail

isDirected

boolean isDirected()

Checks whether this labels is defined as directed.

Returns:

true, if this label is directed, else false.

isUnidirected

boolean isUnidirected()

Checks whether this labels is defined as unidirected.

Returns:

true, if this label is unidirected, else false.

multiplicity

Multiplicity multiplicity()

The Multiplicity for this edge label.

Returns:

mappedProperties

Collection<PropertyKey> mappedProperties()

Collects all property constraints.

Returns:

a list of PropertyKey which represents all property constraints for a EdgeLabel.

mappedConnections

Collection<Connection> mappedConnections()

Collects all connection constraints.

Returns:

a list of Connection which represents all connection constraints for a EdgeLabel.