Retrofit + Observable - 预期为 BEGIN_ARRAY 但为 BEGIN_OBJECT

Question

我正在尝试将 New York Times API 与使用 Observable 的 Retrofit 结合使用。但是我在尝试使用数据时遇到了这个错误。

谁能帮我看看我哪里错了？

这是我的 ApiServices 接口：

@GET("svc/topstories/v2/home.json?api-key=HiddenApiKeyJustForThisMessage")
Observable<TopStoryResult> getTopStories();

@GET("svc/topstories/v2/home.json?api-key=HiddenApiKeyJustForThisMessage")
Observable<List<NewsItem>> getResults();


Retrofit retrofit = new Retrofit.Builder()
        .baseUrl("https://api.nytimes.com/")
        .addConverterFactory(GsonConverterFactory.create(new GsonBuilder().excludeFieldsWithoutExposeAnnotation().create()))
        .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
        .build();

这是我的 ApiStreams 类

public static Observable<TopStoryResult> streamFetchTopStories(){
    ApiServices mApiServices = ApiServices.retrofit.create(ApiServices.class);
    return mApiServices.getTopStories()
            .subscribeOn(Schedulers.io())
            .observeOn(AndroidSchedulers.mainThread())
            .timeout(10, TimeUnit.SECONDS);
}

public static Observable<List<NewsItem>> streamFetchNews(){
    ApiServices mApiServices = ApiServices.retrofit.create(ApiServices.class);
    return mApiServices.getResults()
            .subscribeOn(Schedulers.io())
            .observeOn(AndroidSchedulers.mainThread())
            .timeout(10, TimeUnit.SECONDS);
}

这就是我在 MainActivity 中尝试做的事情。现在我只想在 TextView 中显示每个标题的列表...

//------------------------
// Update UI
//------------------------
private void updateUIWhenStartingHttpRequest() {
    this.textView.setText("Downloading...");
}


private void updateUIWhenStopingHttpRequest(String response) {
    this.textView.setText(response);
}



//------------------------
// Rx Java
//------------------------
private void executeRequestWithRetrofit(){
    this.updateUIWhenStartingHttpRequest();

    this.disposable = ApiStreams.streamFetchNews()
            .subscribeWith(new DisposableObserver<List<NewsItem>>(){

                @Override
                public void onNext(List<NewsItem> topStories) {
                    Log.e("TAG", "On Next");
                    updateUIWithResult(topStories);
                }

                @Override
                public void onError(Throwable e) {
                    Log.e("ERROR", Log.getStackTraceString(e));
                }

                @Override
                public void onComplete() {
                    Log.e("TAG", "On Complete !");
                }
            });
}



private void updateUIWithResult(List<NewsItem> newsItemList){
    StringBuilder mStringBuilder = new StringBuilder();
    for (NewsItem news : newsItemList){
        Log.e("TAG", "UPDATE UI" + news.getTitle());
        mStringBuilder.append("- " + news.getTitle() + "\n");
    }
    updateUIWhenStopingHttpRequest(mStringBuilder.toString());
}

[编辑] TopStories 和 NewsItem 有我的两个模型

热门故事：

private String status;
private String copyright;
private String section;
private String lastUpdated;
private Integer numResults;
private List<NewsItem> results = null;

public String getStatus() {return status;
}

public void setStatus(String status) {
    this.status = status;
}

public String getCopyright() {
    return copyright;
}

public void setCopyright(String copyright) {
    this.copyright = copyright;
}

public String getSection() {
    return section;
}

public void setSection(String section) {
    this.section = section;
}

public String getLastUpdated() {
    return lastUpdated;
}

public void setLastUpdated(String lastUpdated) {
    this.lastUpdated = lastUpdated;
}

public Integer getNumResults() {
    return numResults;
}

public void setNumResults(Integer numResults) {
    this.numResults = numResults;
}

public List<NewsItem> getResults() {
    return results;
}

public void setResults(List<NewsItem> results) {
    this.results = results;
}

新闻项目：

 private String section;
private String subsection;
private String title;
private String url;
private String byline;
private String updated_date;
private String created_date;
private String published_date;
private String material_type_facet;
private String kicker;


@SerializedName("abstract")
private String abstract_string;

private List<Multimedia> multimedia;


private transient String des_facet;
private transient String org_facet;
private transient String per_facet;
private transient String geo_facet;

public NewsItem() {
}

public NewsItem(String url) {
    this.url = url;
}

public NewsItem(String section, String subsection, String title, String url, String byline, String updated_date, String created_date, String published_date, String material_type_facet, String kicker) {
    this.section = section;
    this.subsection = subsection;
    this.title = title;
    this.url = url;
    this.byline = byline;
    this.updated_date = updated_date;
    this.created_date = created_date;
    this.published_date = published_date;
    this.material_type_facet = material_type_facet;
    this.kicker = kicker;
}

public String getSection() {
    return section;
}

public void setSection(String section) {
    this.section = section;
}

public String getSubsection() {
    return subsection;
}

public void setSubsection(String subsection) {
    this.subsection = subsection;
}

public String getTitle() {
    return title;
}

public void setTitle(String title) {
    this.title = title;
}

public String getUrl() {
    return url;
}

public void setUrl(String url) {
    this.url = url;
}

public String getByline() {
    return byline;
}

public void setByline(String byline) {
    this.byline = byline;
}

public String getUpdated_date() {
    return updated_date;
}

public void setUpdated_date(String updated_date) {
    this.updated_date = updated_date;
}

public String getCreated_date() {
    return created_date;
}

public void setCreated_date(String created_date) {
    this.created_date = created_date;
}

public String getPublished_date() {
    return published_date;
}

public void setPublished_date(String published_date) {
    this.published_date = published_date;
}

public String getMaterial_type_facet() {
    return material_type_facet;
}

public void setMaterial_type_facet(String material_type_facet) {
    this.material_type_facet = material_type_facet;
}

public String getKicker() {
    return kicker;
}

public void setKicker(String kicker) {
    this.kicker = kicker;
}


public String getAbstract() {
    return abstract_string;
}

public void setAbstract(String abstract_string) {
    this.abstract_string = abstract_string;
}

public List<Multimedia> getMultimedia() {
    return multimedia;
}

public void setMultimedia(List<Multimedia> multimedia) {
    this.multimedia = multimedia;
}

public String getDes_facet() {
    return des_facet;
}

public void setDes_facet(String des_facet) {
    this.des_facet = des_facet;
}

public String getOrg_facet() {
    return org_facet;
}

public void setOrg_facet(String org_facet) {
    this.org_facet = org_facet;
}

public String getPer_facet() {
    return per_facet;
}

public void setPer_facet(String per_facet) {
    this.per_facet = per_facet;
}

public String getGeo_facet() {
    return geo_facet;
}

public void setGeo_facet(String geo_facet) {
    this.geo_facet = geo_facet;
}

这是 JSON 的样子：

JSON

首先，当我使用 Github 用户 API 尝试这个时，它运行良好。但是我不知道我错在哪里......

有人可以帮帮我吗？

非常感谢！

Answer 1

应为 BEGIN_ARRAY，但为 BEGIN_OBJECT 这意味着您正在尝试将 JSON 数组作为 JAVA 中的列表获取，但 api 向您发送了 JSON OBJECT。所以我无法收集到足够的信息，但如果我不得不猜测你应该改变这个

@GET("svc/topstories/v2/home.json?api-key=HiddenApiKeyJustForThisMessage")
Observable<List<NewsItem>> getResults();

到

@GET("svc/topstories/v2/home.json?api-key=HiddenApiKeyJustForThisMessage")
Observable<NewsItemObject> getResults();

NewsItemObject 是包装 NewsItem 的类

Answer 2

在您的 ApiServices 界面中，您希望 getResults() 返回 Observable<List<NewsItem>>。基于 JSON，您将无法返回，因为您的根 JSON 元素是 Object，而不是 Array。

您必须创建新的包装类 (ResultsWrapper)，“结果”字段类型为 List<NewsItem>。您在 ApiServices 接口中的方法将是：

@GET("svc/topstories/v2/home.json?api-key=HiddenApiKeyJustForThisMessage")
Observable<ResultsWrapper> getResults();

这就是“预期为 BEGIN_ARRAY，但为 BEGIN_OBJECT”的意思。