GraphDB GeoSPARQL Plugin

This is the GraphDB GeoSPARQL plugin. More information about it is available in the GraphDB documentation here: http://graphdb.ontotext.com/documentation/enterprise/geosparql-support.html

Building the plugin

The plugin is a Maven project targeting GraphDB 11. JDK 21 is required to build the plugin and run it in GraphDB.

Run mvn clean package to build the plugin and execute the tests.

The package lifecycle also inspects the assembled plugin ZIP without Docker. It verifies that the plugin and supported Apache SIS Derby runtime are present and that test-only or legacy CRS provider dependencies are absent.

The tests use the test-scoped Apache SIS sis-embedded-data dependency, whose EPSG data is subject to the EPSG Terms of Use. This dependency is not included in the assembled plugin.

The built plugin can be found in the target directory:

• geosparql-plugin-graphdb-plugin.zip

Packaging smoke test

The opt-in packaging smoke test requires Docker. It builds a temporary GraphDB 10.8.12 image with Java 21, installs the assembled plugin ZIP, and uses externally supplied Apache SIS data to run an EPSG:3006 GeoSPARQL property relation and five-metre distance filter function alongside a CRS84 property relation:

mvn -Pgraphdb-packaging-smoke verify

This test checks that the assembled plugin loads and executes in GraphDB with externally supplied Apache SIS CRS data. It does not establish GraphDB 10.8 support or replace validation against the target GraphDB 11 runtime.

Installing the plugin

External plugins are installed under lib/plugins in the GraphDB distribution directory. To install the plugin follow these steps:

1. Remove lib/plugins/geosparql-plugin. Also remove lib/plugins/graphdb-geosparql-plugin if it exists from an older installation.
2. Unzip the built zip file in lib/plugins. This creates lib/plugins/geosparql-plugin.
3. Restart GraphDB.

Rebuilding the GeoSPARQL index

Rebuilding regenerates the GeoSPARQL Lucene index from the current repository data and applies the currently configured index settings. Run a rebuild when GraphDB reports an incompatible GeoSPARQL index, after changing index settings such as the prefix tree or precision, or whenever the index needs to be recreated from repository data.

If the plugin is disabled, enabling it performs a full index build. If the plugin is already enabled, run this SPARQL update to force a rebuild:

PREFIX plugin: <http://www.ontotext.com/plugins/geosparql#>

INSERT DATA {
  [] plugin:forceReindex true
}

The update runs synchronously and may take significant time for a large repository. GraphDB logs Initializing force reindexing process when the rebuild starts and Indexing completed when the indexing work finishes. If the rebuild fails, resolve the reported geometry, CRS-data, storage, or configuration problem and run the update again.

CRS data

The plugin works out of the box for CRS84/default GeoSPARQL geometry data. The default plugin package does not bundle the optional Apache SIS sis-embedded-data EPSG dataset or national grid-shift files. CRSes outside the small subset built into Apache SIS require CRS data supplied to GraphDB through SIS_DATA.

See GeoSPARQL CRS Deployment for setup, validation, error handling, and troubleshooting.