Problema com converter

Farm

public class Farm {

	private Long id;
	private String name;
	private Polygon perimeter;

	public Farm() {
	}

	public Long getId() {
		return id;
	}
	public void setId(Long id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	
	public Polygon getPerimeter() {
		return perimeter;
	}
	public void setPerimeter(Polygon perimeter) {
		this.perimeter = perimeter;
	}
}

FarmController

import javax.inject.Inject;

import br.com.agrofficio.kpifarm.annotation.Security;
import br.com.agrofficio.kpifarm.model.Farm;
import br.com.caelum.vraptor.Consumes;
import br.com.caelum.vraptor.Controller;
import br.com.caelum.vraptor.Path;
import br.com.caelum.vraptor.Post;
import br.com.caelum.vraptor.Result;
import br.com.caelum.vraptor.view.Results;

@Controller
@Path("/api/client/farms")
public class FarmController {

	@Inject
	private Result result;

	public FarmController() {
	}

	@Post("")
	@Consumes("application/json")
	public void add(Farm data) {
		result.use(Results.json()).from(data).recursive().serialize();
	}

}

PolygonConverter

import javax.annotation.Priority;
import javax.enterprise.context.RequestScoped;
import javax.enterprise.inject.Alternative;
import javax.interceptor.Interceptor;

import br.com.caelum.vraptor.Convert;
import br.com.caelum.vraptor.converter.Converter;

import com.vividsolutions.jts.geom.Polygon;

@Convert(Polygon.class)
public class PolygonConverter implements Converter<Polygon> {

	@Override
	public Polygon convert(String value, Class<? extends Polygon> type) {
		return null;
	}

}