This project has retired. For details please refer to its Attic page.
Apache Stanbol - Entityhub Dereference Engine

Entityhub Dereference Engine

This is an Entity Dereference Engine for the Stanbol Entityhub. It supports dereferencing Entities from


The following figure shows the configuration dialog of the Entityhub Dereference Engine:

Entityhub Dereference Engine Configuration Dialog

The following Configuration parameter are defined by the core Entity Dereference Engine. Actual Dereference Engine implementations might not support all of them.

Additional Supported Properties that are not included in the configuration form:

Shared Thread Pool Configuration

The Shared Thread Pool is a singelton Component used by all Entityhub Dereference Engines with the 'Use Shared Thread Pool' option enabled. It has only a single configuration option (enhancer.engines.dereference.entityhub.sharedthreadpool.size) that allows to set the size of the thread pool.

Shared Thread Pool Configuration

Advanced Dereference Configurations

Entityhub Field Mapping Support

The enhancer.engines.dereference.fields configuration does support the Entityhub Field Mapping language.

FieldMappings do use the following syntax:

[!]FieldPattern [| Filter] [> Mapping]

NOTE that Field Mappings configured for the EntityhubDerefereceEngine are overridden by Field Mappings parsed as Enhancement Properties.

LDPath support

The use ofLD Path Language is an alternative to most of the features supported by the Entityhub Field Mapping language. Especially Filters and Mapping SHOULD BE expressed using LD Path.

The only advantage of the Field Mapping language is that is supports the use of wildcards and exclusions. So in cases where one once to dereference all properties of a specific namespace it is only possible to specify this by using the Field Mapping language.

The following Example shows a configuration that dereferences all properties and also uses LD Path to align soem none properties

enhancer.engines.dereference.ldpath=["@prefix schema <>;",
    "@prefix dct <>;",
    "schema:name = (rdfs:label | dct:title | dc:title | foaf:name | skos:prefLabel);",
    "schema:alternateName = skos:altLabel;"
    "schema:image = foaf:depiction;",
    "schema:homepage = foaf:homepage;"]

NOTE when used in a OSGI *.cfg file one would need to escape spaces and = with \ and remove all line breaks.

Supported Enhancement Properties

since version 0.12.1 with STANBOL-1287

The following Enhancement Properties are supported by the Entityhub Dereference Engine

As an example the following query parameter would instruct all Entityhub Dereference engines used in an enhancement engine to just dereference English and German literals.

curl -X POST -H "Accept: text/turtle" -H "Content-type: text/plain" \
    --data "The Eifeltower is located in Paris."