使用改造从 api 获取响应以在 recycleview 中获取响应时出错

Question

我正在尝试使用此 api 联网：https : //api.jikan.moe/v3/schedule所以我通过创建 ApiClient.java 类来使用改造，这是它的代码：public class ApiClient {public static final String BASE_URL = "http://api.themoviedb.org/3/";private static Retrofit retrofit = null;public static Retrofit getClient() {    if (retrofit==null) {        retrofit = new Retrofit.Builder()                .baseUrl(BASE_URL)                .addConverterFactory(GsonConverterFactory.create())                .build();    }    return retrofit;}}完整的链接端点的接口是这样的：public interface ApiInterface {    @GET("schedule")    Call<MainResponse> getSchedule();}所以我在建模数据中使用了可序列化，并创建了 MainResponse.java 类来获取 api 中的主要 monday 数组：公共类 MainResponse {@SerializedName("monday")private List<Schedule> monday;public List<Schedule> getMonday() {    return monday;}public void setMonday(List<Schedule> monday) {    this.monday = monday;}}然后我创建一个新的建模类来获取类 Schedule.java 中 monday 数组的对象项列表：public class Schedule {    @SerializedName("title")    private String title;    public Schedule(String title) {        this.title = title;    }    public String getTitle() {        return title;    }    public void setTitle(String title) {        this.title = title;    }}最后在 MainActivity 我称之为：final RecyclerView recyclerView = (RecyclerView) findViewById(R.id.schedule_recycler_view);        recyclerView.setLayoutManager(new LinearLayoutManager(this));        ApiInterface apiService =                ApiClient.getClient().create(ApiInterface.class);        Call<MainResponse> call = apiService.getSchedule();        call.enqueue(new Callback<MainResponse>() {正如你所看到的，我使用了一个 recycleview 来获取 monday 数组的标题，但问题是当我运行应用程序时，它只是因为这个而崩溃：尝试在空对象引用上调用虚拟方法“java.util.List com.example.user_pc.capstonestage2.MainResponse.getMonday()”

Answer 1

您已声明错误的 API URL 是：

public static final String BASE_URL = "https://api.jikan.moe/v3/";

你MainResponse应该是这样的：

public class MainResponse {

@SerializedName("request_hash")

@Expose

private String requestHash;

@SerializedName("request_cached")

@Expose

private Boolean requestCached;

@SerializedName("request_cache_expiry")

@Expose

private Integer requestCacheExpiry;

@SerializedName("monday")

@Expose

private List<Monday> monday = null;

public String getRequestHash() {

return requestHash;

}

public void setRequestHash(String requestHash) {

this.requestHash = requestHash;

}

public Boolean getRequestCached() {

return requestCached;

}

public void setRequestCached(Boolean requestCached) {

this.requestCached = requestCached;

}

public Integer getRequestCacheExpiry() {

return requestCacheExpiry;

}

public void setRequestCacheExpiry(Integer requestCacheExpiry) {

this.requestCacheExpiry = requestCacheExpiry;

}

public List<Monday> getMonday() {

return monday;

}

public void setMonday(List<Monday> monday) {

this.monday = monday;

}

}

该Genre班

public class Genre {

@SerializedName("mal_id")

@Expose

private Integer malId;

@SerializedName("type")

@Expose

private String type;

@SerializedName("name")

@Expose

private String name;

@SerializedName("url")

@Expose

private String url;

public Integer getMalId() {

return malId;

}

public void setMalId(Integer malId) {

this.malId = malId;

}

public String getType() {

return type;

}

public void setType(String type) {

this.type = type;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public String getUrl() {

return url;

}

public void setUrl(String url) {

this.url = url;

}

}

最后是Monday班级

public class Monday {

@SerializedName("mal_id")

@Expose

private Integer malId;

@SerializedName("url")

@Expose

private String url;

@SerializedName("title")

@Expose

private String title;

@SerializedName("image_url")

@Expose

private String imageUrl;

@SerializedName("synopsis")

@Expose

private String synopsis;

@SerializedName("type")

@Expose

private String type;

@SerializedName("airing_start")

@Expose

private String airingStart;

@SerializedName("episodes")

@Expose

private Integer episodes;

@SerializedName("members")

@Expose

private Integer members;

@SerializedName("genres")

@Expose

private List<Genre> genres = null;

@SerializedName("source")

@Expose

private String source;

@SerializedName("producers")

@Expose

private List<Object> producers = null;

@SerializedName("score")

@Expose

private Object score;

@SerializedName("licensors")

@Expose

private List<Object> licensors = null;

@SerializedName("r18")

@Expose

private Boolean r18;

@SerializedName("kids")

@Expose

private Boolean kids;

public Integer getMalId() {

return malId;

}

public void setMalId(Integer malId) {

this.malId = malId;

}

public String getUrl() {

return url;

}

public void setUrl(String url) {

this.url = url;

}

public String getTitle() {

return title;

}

public void setTitle(String title) {

this.title = title;

}

public String getImageUrl() {

return imageUrl;

}

public void setImageUrl(String imageUrl) {

this.imageUrl = imageUrl;

}

public String getSynopsis() {

return synopsis;

}

public void setSynopsis(String synopsis) {

this.synopsis = synopsis;

}

public String getType() {

return type;

}

public void setType(String type) {

this.type = type;

}

public String getAiringStart() {

return airingStart;

}

public void setAiringStart(String airingStart) {

this.airingStart = airingStart;

}

public Integer getEpisodes() {

return episodes;

}

public void setEpisodes(Integer episodes) {

this.episodes = episodes;

}

public Integer getMembers() {

return members;

}

public void setMembers(Integer members) {

this.members = members;

}

public List<Genre> getGenres() {

return genres;

}

public void setGenres(List<Genre> genres) {

this.genres = genres;

}

public String getSource() {

return source;

}

public void setSource(String source) {

this.source = source;

}

public List<Object> getProducers() {

return producers;

}

public void setProducers(List<Object> producers) {

this.producers = producers;

}

public Object getScore() {

return score;

}

public void setScore(Object score) {

this.score = score;

}

public List<Object> getLicensors() {

return licensors;

}

public void setLicensors(List<Object> licensors) {

this.licensors = licensors;

}

public Boolean getR18() {

return r18;

}

public void setR18(Boolean r18) {

this.r18 = r18;

}

public Boolean getKids() {

return kids;

}

public void setKids(Boolean kids) {

this.kids = kids;

}

}

Answer 2

您的 api 链接是https://api.jikan.moe/v3/schedule 但在您编写的代码中

public static final String BASE_URL = "http://api.themoviedb.org/3/";

您可以将基本 url 更改为https://api.jikan.moe/v3/，或者

在 getSchedule() 的 GET 注释上提供完整的 url

 @GET("https://api.jikan.moe/v3/schedule")

 Call<MainResponse> getSchedule();