Restler is a library that automatically generates a client for a web service at run time, by analyzing the respective annotated Spring controller interface. Restler may help you remove HTTP-specific boilerplate from your integration tests, microservices and thirdparty HTTP API clients.

EPA warning: Restler currently is in early public access stage and it is neither feature complete, tested in production or backward compatible

• Easily extensible architecture
• Custom authentication, authorization and errors mapping strategies
• Support of form-based, http basic, cookie-based and generic header-based authentication
• Support of async controllers through methods returning Future, DefferedResult or Callable objects
• Experemental Spring Data REST support

Suppose you have the following interface on the server:

/** 
  * An annotated Spring controller interface
  */
@Controller
@RequestMapping("greeter")
public interface Greeter {

	@RequestMapping("greetings/{language}")	
	String getGreeting(@PathVariable String language, @RequestParam(defaultValue = "Anonymous") String name); 

}

Then in your client you can invoke the getGreeting method of the remote service using the following code snippet:

Service service = new Restler("https://www.example.com/api", new SpringMvcSupport()).build();
Greeter greeter = service.produceClient(Greeter.class);
String greeting = greeter.getGreeting("en","Buddy"); // the result of https://www.example.com/api/greeter/greetings/en?name=Buddy call