src-openfeign/jaxrs

Feign JAXRS

This module overrides annotation processing to instead use standard ones supplied by the JAX-RS specification. This is currently targeted at the 1.1 spec.

Limitations

While it may appear possible to reuse the same interface across client and server, bear in mind that JAX-RS resource annotations were not designed to be processed by clients. Moreover, JAX-RS 2.0 has a different package hierarchy for client invocation. Finally, JAX-RS is a large spec and attempts to implement it completely would be a project larger than feign itself. In other words, this implementation is best efforts and concedes far from 100% compatibility with server interface behavior.

Currently Supported Annotation Processing

Feign only supports processing java interfaces (not abstract or concrete classes).

Here are a list of behaviors currently supported.

Type Annotations

@Path

Appends the value to Target.url(). Can have tokens corresponding to @PathParam annotations.

Method Annotations

@HttpMethod meta-annotation (present on @GET, @POST, etc.)

Sets the request method.

@Path

Appends the value to Target.url(). Can have tokens corresponding to @PathParam annotations.

@Produces

Adds all values into the Accept header.

@Consumes

Adds the first value as the Content-Type header.

Parameter Annotations

@PathParam

Links the value of the corresponding parameter to a template variable declared in the path.

@QueryParam

Links the value of the corresponding parameter to a query parameter. When invoked, null will skip the query param.

@HeaderParam

Links the value of the corresponding parameter to a header.

@FormParam

Links the value of the corresponding parameter to a key passed to Encoder.Text<Map<String, Object>>.encode().