Application.java

package controllers;

import play.mvc.*;

import com.google.gson.*;

import models.*;

public class Application extends Controller {

    public static void handleJson(JsonObject body) {
        renderText(body.getAsJsonPrimitive("name").getAsString());
    }
    
    public static void handleJsonAsObject(JsonObject body) {
        User u = new Gson().fromJson(body, User.class);
        renderText(u);
    }

}

GsonBinder.java

package utils;

import java.lang.annotation.*;

import com.google.gson.*;

import play.data.binding.*;

@Global
public class GsonBinder implements TypeBinder<JsonObject> {

    public Object bind(String name, Annotation[] antns, String value, Class type) throws Exception {
        return new JsonParser().parse(value);
    }
}