DBpedia Lookup is a web service that can be used to look up DBpedia URIs by related keywords. Related means that either the label of a resource matches, or an anchor text that was frequently used in Wikipedia to refer to a specific resource matches (for example the resource http://dbpedia.org/resource/United_States can be looked up by the string "USA"). The results are ranked by the number of inlinks pointing from other Wikipedia pages at a result page.
Two APIs are offered: Keyword Search and Prefix Search. A hosted version of the Lookup service is available on the DBpedia server infrastructure.
The Keyword Search API can be used to find related DBpedia resources for a given string. The string may consist of a single or multiple words.
Example: Places that have the related keyword "berlin"
http://lookup.dbpedia.org/api/search/KeywordSearch?QueryClass=place&QueryString=berlin
The Prefix Search API can be used to implement autocomplete input boxes. For a given partial keyword like berl the API returns URIs of related DBpedia resources like http://dbpedia.org/resource/Berlin.
Example: Top five resources for which a keyword starts with "berl"
http://lookup.dbpedia.org/api/search/PrefixSearch?QueryClass=&MaxHits=5&QueryString=berl
The query parameters accepted by the endpoints are
QueryString: a string for which a DBpedia URI should be found.QueryClass: a DBpedia class from the Ontology that the results should have (for owl#Thing and untyped resource, leave this parameter empty).MaxHits: the maximum number of returned results (default: 5)
By default all data is returned as XML, the service also retuns JSON to any request including the Accept: application/json header.
git clone git://github.com/dbpedia/lookup.git
cd lookup
mvn clean install
Rebuilding an index is required if you want to use the 2016 version of DBPedia.
To re-build the index you will require
* DBpedia datasets
### Get the following DBpedia datasets
from http://downloads.dbpedia.org/2016-10/core-i18n/en/
* redirects\_en.ttl (Redirects are not indexed, but they are excluded as targets of lookup.)
* short\_abstracts\_en.ttl
* instance\_types\_en.ttl --> it is beter to rename this one to: core_instances.ttl
* article\_categories\_en.ttl
from http://downloads.dbpedia.org/2016-10/core/
* instance_types_en.ttl
* instance_types_lhd_dbo_en.ttl
* instance_types_transitive_en.ttl
### Concatenate all data and sort by URI
This is necessary because indexing in sorted order is significantly faster.
cat core_instances.ttl \
short_abstracts_en.ttl \
article_categories_en.ttl \
instance_types_en.ttl \
instance_types_lhd_dbo_en.ttl \
instance_types_transitive_en.ttl | sort >all_dbpedia_data..ttl
The indexer has to be run twice:
1. with the DBpedia data
./run Indexer lookup_index_dir redirects_en..ttl all_dbpedia_data.nt .ttl
(this code will make the segementation files needed to run dbpeida lookup)
`./run Server lookup_index_dir`
lookup_index_dir is the directory created by Run Indexer (previous step)
E.g:
`./run Server ..`
- en - English
but you can change the language by indexing other files
The server should now be running at http://localhost:1111
The best way to get support or give feedback on the Lookup project is via the DBpedia discussion mailing list. More technical queries about the code base should be directed to the DBpedia developers mailing list.
The DBpedia wiki also has useful information on the project.
- Kunal Jha @Kunal-Jha
- Sandro Coelho @sandroacoelho
- Pablo Mendes @pablomendes (less active)
- Max Jakob @maxjakob (less active)
- Matt Haynes @matth (less active)