Remote proxy REST methods

Goals:

• Simplify how remoteable interface proxies are exposed in the server and used in the clients.
• Allow interface proxies to be defined against 3rd-party REST interfaces.
• Allow interface proxies to pass Java method parameters as GET parameters.

New annotations:

• @Remotable
  Annotation applied to interface proxy classes. 
• path(String), optional 
  The absolute or relative path to the REST service.
  When relative path is specified, it's relative to the root-url defined on the RestClient.
   
• expose(String), optional
  Defines the methods on the interface that are visible.
  Possible values:
  • "ALL" (default) - All methods defined on the interface are visible.
  • "REMOTEABLE" - Only methods marked with the @RemoteableMethod annotation are visible.
    
    
• @RemoteableMethod
  Annotation applied to Java methods on interface proxy classes. 
  
  
  • path(String), optional
    The path to the REST service for this Java method.
    The default value is the Java method name itself.
    
    
  • httpMethod(String), optional
    Defines whether to use GET or POST for the method call.
    Possible values:
    • "POST" (default) - Parameters are serialized using the serializer registered with the RestClient.
    • "GET" - Parameters are serialized using the UrlEncodingSerializer registered with the RestClient.
      
      

Example:

@Remoteable(url="/myremoteableinterface")
public interface MyRemoteableInterface {

   @RemoteableMethod(httpMethod="GET", path="/method1")
   public Foo callMyMethod(@Param("bar") int bar, @Param("baz") String baz, @Param("qux") Bean qux);
}

RestClient client = RestClientBuilder().rootUrl("http://hostname").build();
MyRemoteableInterface i = client.getRemoteableProxy(MyRemoteInterface.class);
Foo f = i.callMyMethod(123,"foo",new Bean()); 

The code above causes the following HTTP request:

HTTP GET http://hostname/myremoteableinterface/method1?bar=123&baz=foo&qux=(...)