检查API响应中的空值

Question

我有一个api，当它是收视率最高的电影时，会返回等值

[
{
"movieId":"o1",
"movie name":"Dory",
"rating":"Best"
}
]

如果没有，则返回

[
{
"movieId":null,
"movie name":null,
"rating":null
}
]

我使用了一个rest模板，该模板使用执行方法调用api

public List<Movies> getRatingViaApi(String id){

RestTemplate restTemplate = new RestTemplate();
//String resourceUrl = "http://localhost:8080/movies";


RequestCallback requestCallback = request -> {
ObjectMapper mapper = new ObjectMapper();
mapper.writeValue(request.getBody(), 
id);
request.getHeaders()
.setAccept(Arrays.asList(
MediaType.APPLICATION_OCTET_STREAM, 
MediaType.ALL));
};

ResponseExtractor<List<Movies>> responseExtractor = response -> 
ObjectMapper mapper= new ObjectMapper ();
return mapper.readValue(response.getBody(),new TypeReference<List<Movies>>(){});
};
restTemplate.execute(resourceUrl, 
HttpMethod.GET, 
requestCallback, 
responseExtractor );    
}

如何检查Api响应是否给出空值或者它是否是最好的电影

Answer 1

你想要这样的东西吗？

@Data
public class Movies {
private static final String THE_BEST_RATING = "Best";
private String movieId;
private String movieName;
private String rating;
public boolean isPresent() {
return ObjectUtils.allNull(movieId, movieName, rating);
}
public boolean isTheBest() {
return Objects.equals(THE_BEST_RATING, rating);
}
}

使用示例：

public static void main(String[] args) {
// ...
// download list
List<Movies> existingMovies = moviesList.stream() // list of "non null objects"
.filter(Movies::isPresent)
.collect(toCollection(ArrayList::new));
existingMovies.stream()
.filter(Movies::isTheBest)
.forEach(movie -> System.out.println("Movie: " + movie + " is the best")); //printing the bests movies
}