JSON Providers

Apache Wink provides a set providers that are capable of serializing a number of data models into JSON representations. There are currently 3 Apache Wink extensions that provide JSON support. Each has unique features that may make one more suitable for your particular application.

wink-json-provider (org.json)

The wink-json-provider extension is provided in the binary distribution and uses the JSON.org classes to provide JSON support. Include the wink-json-provider-<VERSION>.jar in the classpath and the providers will automatically be registered. You will also need the org.json JAR which is provided in the ext/wink-json-provider/lib folder.

org.apache.wink.providers.json.JsonProvider

Handles reading and writing of org.json.JSONObject classes for the application/json and application/javascript media types.

org.apache.wink.providers.json.JsonArrayProvider

Handles reading and writing of org.json.JSONArray classes for the application/json and application/javascript media types.

org.apache.wink.providers.json.JsonJAXBProvider

Handles reading and writing of JAXBElement and JAXB annotated classes for the application/json and application/javascript media types.

Producing and Consuming JSON Example

The following example demonstrates the usage of a JSON provider for reading and writing JSON representations.

    @GET
    @Consumes(MediaType.APPLICATION_JSON)
    @Produces(MediaType.APPLICATION_JSON)
    public JSONObject postJSON(JSONObject requestJSON) {
        String property = requestJSON.getString("property");
        JSONObject jobj = new JSONObject();
        return jobj;
    }

    /* Book is a JAXB annotated class */

    @GET
    @Consumes(MediaType.APPLICATION_JSON)
    @Produces(MediaType.APPLICATION_JSON)
    public Book postJSONBook(Book requestBookEntity) {
        String title = requestBookEntity.getTitle();
        /* other code */
        Book response = new Book();
        return response;
    }

wink-jettison-provider (org.codehaus.jettison)

The wink-jettison-provider extension is provided in the binary distribution and uses the Jettison code to provide JSON support. Include the wink-jettison-provider-<VERSION>.jar in the classpath and the providers will automatically be registered. You will also need the Jettison library JARs which are provided in the ext/wink-jettison-provider/lib folder.

By default, reading is currently disabled due to potential issues with the reader. You can enable it by calling setUseAsReader(boolean) on each provider and registering as a singleton in the JAX-RS Application sub-class.

org.apache.wink.providers.jettison.JettisonJAXBElementProvider

Handles reading and writing of JAXBElement classes for the application/json media type.

org.apache.wink.providers.jettison.JettisonJAXBElementProvider

Handles reading and writing of JAXB annotated classes for the application/json media type.

Example

The following examples demonstrates the usage of a Jettison provider for producing and consuming JSON.

Jettison Provider Registration

The following code example demonstrates the way to register a Jettison provider within a JAX-RS application.

    public class MyApp extends Application {
        public Set getClasses() {
            Set s = new HashSet();
            s.add(MyResource.class);
            return s;
        }

        public Set<Object> getSingletons() {
            Set s = new HashSet();
            JettisonJAXBProvider jaxbProvider = new JettisonJAXBProvider();
            jaxbProvider.setUseAsReader(true);
            return s;
        }
    }

Producing and Consuming JSON

The following code example demonstrates the reading and writting of JAXB objects into a JSON representation by using a Jettison provider.

    /* Book is a JAXB annotated class */

    @GET
    @Consumes(MediaType.APPLICATION_JSON)
    @Produces(MediaType.APPLICATION_JSON)
    public Book postJSONBook(Book requestBookEntity) {
        String title = requestBookEntity.getTitle();
        /* other code */
        Book response = new Book();
        return response;
    }

Jackson JSON Processor

Jackson JSON Processor may also suit your needs and can be used. They provide their own JAX-RS entity provider. See their documentation for more information.