Jersey client: How to add a list as query parameter

Question

I'm creating a Jersey client for a GET service that has a List as query parameter. According to the documentation, it's possible to have a List as a query parameter (this information is also at @QueryParam javadoc), check it out:

In general the Java type of the method parameter may:

1. Be a primitive type;
2. Have a constructor that accepts a single String argument;
3. Have a static method named valueOf or fromString that accepts a single String argument (see, for example, Integer.valueOf(String) and java.util.UUID.fromString(String)); or
4. Be List, Set or SortedSet, where T satisfies 2 or 3 above. The resulting collection is read-only.

Sometimes parameters may contain more than one value for the same name. If this is the case then types in 4) may be used to obtain all values.

However, I can't figure out how to add a List query parameter using Jersey client.

I understand alternative solutions are:

1. Use POST instead of GET;
2. Transform the List into a JSON string and pass it to the service.

The first one is not good, because the proper HTTP verb for the service is GET. It is a data retrieval operation.

The second will be my option if you can't help me out. :)

I'm also developing the service, so I may change it as needed.

Thanks!

Update

Client code (using json)

Client client = Client.create();

WebResource webResource = client.resource(uri.toString());

SearchWrapper sw = new SearchWrapper(termo, pagina, ordenacao, hits, SEARCH_VIEW, navegadores);

MultivaluedMap<String, String> params = new MultivaluedMapImpl();
params.add("user", user.toUpperCase()); 
params.add("searchWrapperAsJSON", (new Gson()).toJson(sw));

ClientResponse clientResponse = webResource .path("/listar")
                                            .queryParams(params)
                                            .header(HttpHeaders.AUTHORIZATION, AuthenticationHelper.getBasicAuthHeader())
                                            .get(ClientResponse.class);

SearchResultWrapper busca = clientResponse.getEntity(new GenericType<SearchResultWrapper>() {});

Answer 1

@GET does support List of Strings

Setup:
Java : 1.7
Jersey version : 1.9

Resource

@Path("/v1/test")

Subresource:

// receive List of Strings
@GET
@Path("/receiveListOfStrings")
public Response receiveListOfStrings(@QueryParam("list") final List<String> list){
    log.info("receieved list of size="+list.size());
    return Response.ok().build();
}

Jersey testcase

@Test
public void testReceiveListOfStrings() throws Exception {
    WebResource webResource = resource();
    ClientResponse responseMsg = webResource.path("/v1/test/receiveListOfStrings")
            .queryParam("list", "one")
            .queryParam("list", "two")
            .queryParam("list", "three")
            .get(ClientResponse.class);
    Assert.assertEquals(200, responseMsg.getStatus());
}