src-openfeign/jaxrs2/README.md

# Feign JAXRS 2
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).

ISE is raised when any annotation's value is empty or null.  Ex. `Path("")` raises an ISE.

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()`.