Decentralised Content Negotiation

An implementation for the approach enabling decentralised content negotiation. The paper was presented at Data Management for Knowledge Graphs (DMKG - ESWC 2023)

Prerequisites

• Java 9+
• Curl or Postman for testing.

Building the project

To build the project, just use:

./gradlew build

The Gradle task build generates a fat-jar in the build/libs directory.

Running DCN project

To start the project:

java -jar .\build\libs\decentralised-cn-0.0.1-SNAPSHOT.jar

Open your browser to http://localhost:8080. You should see the message DCN project is running ....

Examples

Media Type Dimension

To request an HTML representation of the resource identified by the URI http://www.uniprot.org/taxonomy/3330, send the GET request:

curl -v http://localhost:8080/dcn/api/media-type?iri=http://www.uniprot.org/taxonomy/3330 -H "accept: text/html"

If a request for a Turtle representation of the resource identified by the URI http://www.uniprot.org/taxonomy/3330, is sent directly with the request:

curl -v http://www.uniprot.org/taxonomy/3330 -H "accept: text/turtle"

No adequate representation is served. However, if a request is sent through the API, i.e. send the GET request:

curl -v http://localhost:8080/dcn/api/media-type?iri=http://www.uniprot.org/taxonomy/3330 -H "accept: text/turtle"

A representation is served after utilizing the Equavalance Links such as owl:sameAs to look for potential acceptable representations.

Profile Dimension

A Profile in this implementation is a SHACL shape graphs. Examples of such profiles could be found in the profiles folder.

To ask for a representation of the resource identified by the URI http://www.uniprot.org/taxonomy/3330, that validates the example-shape-graph-1 profile, a request of this type should be sent:

curl -v http://localhost:8080/dcn/api/profile?iri=http://www.uniprot.org/taxonomy/3330 -H "accept-profile: http://localhost:8080/profiles/example-shape-graph-1.ttl"

Similarly, if other profiles are preferred, only a change of the accept-profile header is needed.

Test with Swagger

A Swagger-UI is also available at the address http://localhost:8080/swagger-ui/index.html to enable easy testing if so desired.