kbss-cvut / jb4jsonld-jackson

JSON-LD serialization and deserialization for Java REST services. Jackson integration.

Java Binding for JSON-LD - Jackson

Java Binding for JSON-LD - Jackson (JB4JSON-LD-Jackson) is a binding of JB4JSON-LD for Jackson.

The core implementation of JB4JSON-LD with a mapping example can be found at https://github.com/kbss-cvut/jb4jsonld. The repository also contains Wiki with some basic documentation.

Usage

JB4JSON-LD is based on annotations from JOPA, which enable POJO attributes to be mapped to ontological constructs (i.e. to object, data or annotation properties) and Java classes to ontological classes.

Use @OWLDataProperty to annotate data fields and @OWLObjectProperty to annotate fields referencing other mapped entities.

To integrate the library with Jackson, register a cz.cvut.kbss.jsonld.jackson.JsonLdModule in Jackson's ObjectMapper like this:

objectMapper.registerModule(new JsonLdModule());

and you should be good to go. See the example application in example for a minimalist demo of using JB4JSON-LD Jackson.

https://github.com/kbss-cvut/jopa-examples/tree/master/jsonld provides a more realistic example of JB4JSON-LD-Jackson in action. TermIt is then a real-world information system using JB4JSON-LD.

Serialization

The serializer's output has been verified to be a valid JSON-LD and is parseable by Java's JSON-LD reference implementation jsonld-java.

The output is by default a context-less compacted JSON-LD, which uses full IRIs for attribute names.

Serialization with Context

Since version 0.10.0, it is possible to configure JB4JSON-LD to output compacted JSON-LD with context (@context). This allows better compatibility with legacy applications not supporting JSON-LD. To enable context-based serialization, configure the JsonLdModule as follows:

JsonLdModule module = new JsonLdModule();
module.configure(SerializationConstants.FORM, SerializationConstants.FORM_COMPACT_WITH_CONTEXT);

Deserialization

Since we are using jsonld-java to first process the incoming JSON-LD, it does not matter in which form (expanded, framed, flattened) the input is.

Getting JB4JSON-LD-Jackson

There are two ways to get JB4JSON-LD-Jackson:

• Clone repository/download zip and build it with Maven,
• Use a Maven dependency:

<dependency>
    <groupId>cz.cvut.kbss.jsonld</groupId>
    <artifactId>jb4jsonld-jackson</artifactId>
</dependency>

License

LGPLv3