将对象列表从Android传递到RESTful Webservice

Question

使用Luke的RestClient for Android并将其称为：

    String baseurlString = "http://10.0.2.2:8080/WebTest/jaxrs/ws/testlist";
    RestClient client = new RestClient(baseurlString);

    String list = "<?xml version='1.0' encoding='UTF-8' standalone='yes'?><pairs><pair><_id>1</_id><_version>12</_version></pair></pairs>";
    client.AddParam("list", list);
    client.AddHeader(ContentType, MediaType.UrlEncoded);

    try
    {
        client.Execute(RequestMethod.POST);

    }
    catch (Exception e)
    {
        e.printStackTrace();
    }

    String responseString = client.getResponse();

To Rest方法如下：

@POST
@Path("testlist")
@Consumes("application/x-www-form-urlencoded")
@Produces("application/xml")
public List<Pair> insertList(@FormParam("list") List<Pair> pairs)
{
    return pairs;
}

由于没有List按预期工作：

@POST
@Consumes("application/x-www-form-urlencoded")
@Produces("application/xml")
public Pair insertValue(@FormParam("pair") Pair pair)
{
    return pair;
}

我做错了什么？