这个action怎么测试？

action类大概样子如下：

java 代码

public class GuideLinkGropAction extends BaseAction {

    private GuideLinkGroup guideLinkGroup;

    private TravelBureauService travelBureauService;

    public String getTravelBureauNames() throws Exception {
        List travelBureaulList = travelBureauService
                .findTravelBureaulList(new TravelBureau());
        List travelBureauNamesList = getTravelBureauNameList(travelBureaulList);
        String travelBureauName = guideLinkGroup.getTravelBureau().getUserName();
        responseOut(travelBureauNamesList, travelBureauName);
        return SUCCESS;
    }

    private List getTravelBureauNameList(List travelBureaulList) {
        List list = new ArrayList();
        Iterator iter = travelBureaulList.iterator();
        while (iter.hasNext()) {
            TravelBureau travelBureau = (TravelBureau) iter.next();
            CommonInfo info = new CommonInfo();
            info.setId(travelBureau.getId());
            info.setValue(travelBureau.getUserName());
            list.add(info);
        }
        return list;
    }

    private void responseOut(List travelBureauNamesList, String travelBureauName)
            throws Exception {
        HttpServletResponse response = ServletActionContext.getResponse();
        List matching = CommonUtil.prefixMatch(travelBureauNamesList,
                travelBureauName);
        PrintWriter out = response.getWriter();
        response.setContentType("text/xml");
        response.setHeader("Cache-Control", "no-cache");
        Iterator iter = matching.iterator();
        while (iter.hasNext()) {
            CommonInfo info = (CommonInfo) iter.next();
            String name = new String(info.getValue().getBytes("UTF-8"),
                    "ISO8859-1");
            out.print("<name></name>" + name + "");
            out.println("<id></id>" + info.getId() + "");
        }
        out.println("");
        out.close();
    }
}

上面的getTravelBureauNames方法是为了一个ajax的功能异步获取数据用的，responseOut方法是把数据用xml格式输出，现在要测试getTravelBureauNames方法，怎么测都没有成功，我想的大概测试代码如下：

java 代码 

public class GuideLinkGropActionTest extends TestCase {

    private MockControl control2;

    private TravelBureauService travelBureauService;

    Map session  = new HashMap();

    GuideLinkGropAction action = new GuideLinkGropAction();

    protected void setUp() throws Exception {
        control2 = MockControl.createControl(TravelBureauService.class);
        travelBureauService= (TravelBureauService) control2.getMock();
    }

    public void testGetTravelBureauNames()throws Exception {
        travelBureauService.findTravelBureaulList(new TravelBureau());
        control2.setReturnValue(new ArrayList());
        control2.replay();

        action.setTravelBureauService(travelBureauService);
        assertEquals(Action.SUCCESS, action.getTravelBureauNames());
        control2.verify();
    }
}

这个测试代码肯定是通不过的