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No, this is not the JSONP you are thinking of! JSON-P is a new Java EE 7 JSON parsing API. Horrible name for a new JSON parsing API! What were they thinking? Anyways, RESTEasy has a provider for it. If you are using WildFly, it is required by Java EE 7 so you will have it automatically bundled. Otherwise, use this maven dependency.
<dependency> <groupId>org.jboss.resteasy</groupId> <artifactId>resteasy-json-p-provider</artifactId> <version>4.7.3.Final</version> </dependency>
It has built in support for JsonObject, JsonArray, and JsonStructure as request or response entities. It should not conflict with Jackson if you have that in your path too.