JSON Providers
Apache Wink provides a set of providers that are capable of serializing a number of data models into JSON representations. There are currently 3 three 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.
| Supported | Media Types | Entity |
---|---|---|---|
Read | Yes | application/json , application/javascript | org.json.JSONObject |
Write | Yes | application/json , application/javascript | org.json.JSONObject |
org.apache.wink.providers.json.JsonArrayProvider
Handles reading and writing of org.json.JSONArray classes for the application/json and application/javascript media types.
| Supported | Media Types | Entity |
---|---|---|---|
Read | Yes | application/json , application/javascript | org.json.JSONArray |
Write | Yes | application/json , application/javascript | org.json.JSONArray |
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.
| Supported | Media Types | Entity |
---|---|---|---|
Read | Yes | application/json , application/javascript | JAXB object, |
Write | Yes | application/json , application/javascript | JAXB object, |
Producing and Consuming JSON Example
The following example demonstrates the usage of a JSON provider for reading and writing JSON representations.
Code Block |
---|
@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.
| Supported | Media Types | Entity |
---|---|---|---|
Read | Yes | application/json | JAXBElement<?>>> |
Write | Yes | application/json | JAXBElement<?>>> |
org.apache.wink.providers.jettison.JettisonJAXBElementProvider
Handles reading and writing of JAXB annotated classes for the application/json media type.
| Supported | Media Types | Entity |
---|---|---|---|
Read | Yes | application/json | JAXB object |
Write | Yes | application/json | JAXB object |
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.
Code Block |
---|
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.
Code Block |
---|
/* 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.