46.4. Using Apache CXF extensions
Overview
Apache CXF provides an extension to the standard JAX-WS injection mechanism that allows developers to replace a sequence of injection annotations with a single annotation. The single annotation is placed on a bean containing fields for the data that is extracted using the annotation. For example, if a resource method is expecting a request URI to include three query parameters called
id
, type
, and size
, it could use a single @QueryParam
annotation to inject all of the parameters into a bean with corresponding fields.
Note
Consider using the
@BeanParam
annotation instead (available since JAX-RS 2.0). The standardized @BeanParam
approach is more flexible than the proprietary Apache CXF extension, and is thus the recommended alternative. For details, see Section 46.2.6, “Injecting Parameters into a Java Bean”.
Supported injection annotations
This extension does not support all of the injection parameters. It only supports the following ones:
@PathParam
@QueryParam
@MatrixParam
@FormParam
Syntax
To indicate that an annotation is going to use serial injection into a bean, you need to do two things:
- Specify the annotation's parameter as an empty string. For example
@PathParam("")
specifies that a sequence of URI template variables are to be serialized into a bean. - Ensure that the annotated parameter is a bean with fields that match the values being injected.
Example
Example 46.11, “Injecting query parameters into a bean” shows an example of injecting a number of Query parameters into a bean. The resource method expect the request URI to include two query parameters:
type
and id
. Their values are injected into the corresponding fields of the Monster
bean.
Example 46.11. Injecting query parameters into a bean
import javax.ws.rs.QueryParam; import javax.ws.rs.PathParam; import javax.ws.rs.POST; import javax.ws.rs.Path; ... @Path("/monstersforhire/") public class MonsterService { ... @POST public void updateMonster(@QueryParam("") Monster bean) { ... } ... } public class Monster { String type; String id; ... }