Mockito RestTemplate ResponseEntity给出空指针异常

Question

我是Mockito的新手，面对RestTemplate的空指针异常。有人可以帮忙，让我知道我的模拟服务有什么问题。

服务：

public List<String> getval(String id) {
    String path = "/abc" + id;
    ResponseEntity<tnclass> RE = restTemplate.getForEntity(id, tnClass.class);
    if (RE != null && RE.getStatusCode() == HttpStatus.OK){
        return RE.getBody().gettnNumbers();
    }else{
        return Collections.<String>emptyList();
    }
}

MockService：

private RestTemplate res = mock(RestTemplate.class);

public List<String> getval(String id) {
    ResponseEntity<tnClass> my = mock(ResponseEntity.class);
    tnClass tn = mock(tnClass.class);
    List<String> l = new ArrayList();
    l.add(0, "t1");
    l.add(1, "t2");
    tn.setId(id);
    tn.settnNumbers(l);
    Mockito.when(restTemplate.getForEntity(path, tnClass.class, tn)).thenReturn(my);
    List<String> finallist = my.getBody().gettnNumbers();
    return finallist;
}