If we try to return a JsonOject in jersey, like this

@Path("/formSubmit")
@POST
@Produces("application/json")
public JSONObject formSubmit()
{
    JSONObject json1 =new JSONObject();
    return json1;
} 

it may give an error (org.codehaus.jackson.map.JsonMappingException: No serializer found for class org.json.JSONObject and no properties discovered to create BeanSerializer)

org.codehaus.jackson.map.JsonMappingException: No serializer found for class org.json.JSONObject and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationConfig.Feature.FAIL_ON_EMPTY_BEANS) )
            org.codehaus.jackson.map.ser.impl.UnknownSerializer.failForEmpty(UnknownSerializer.java:52)
            org.codehaus.jackson.map.ser.impl.UnknownSerializer.serialize(UnknownSerializer.java:25)
            org.codehaus.jackson.map.ser.StdSerializerProvider._serializeValue(StdSerializerProvider.java:610)
            org.codehaus.jackson.map.ser.StdSerializerProvider.serializeValue(StdSerializerProvider.java:256)
            org.codehaus.jackson.map.ObjectMapper.writeValue(ObjectMapper.java:1604)

To avoid this , first return a json by using

 @Produces("application/json"). 

This determines that Jersey will know that the output is in json format.

Now inspite of using JSONObject, we can use any class and transform it in json by putting

@XmlRootElement
public class Employee {} 

Here, json will represent all the attributes of class.

@POST
@Consumes("application/json")
public Employee formSubmit(){
return employee;
}