预期开始数组，但在改造中出现开始对象错误

Posted 2023-04-19

【中文标题】预期开始数组，但在改造中出现开始对象错误

【英文标题】：Expected Begin Array but was Begin Object error in Retrofit

【发布时间】：2021-05-03 23:50:31

【问题描述】：

我是改造库的新手，在获得响应时遇到此错误， 下面是我的 JSON 响应和 Java 代码：

当我敬酒时，它给了我“预期的开始数组但是开始对象”的响应。我想将我的结果存储在 listview 中，并且我已经设置了我的视图并分配了值。但我无法从我使用的 API 获得响应。

我已经从 json2pojoschema 网站复制了我的模型类，所以模型类应该没有任何问题。如果仍然需要，请告诉我。

JSON：

    "destination_addresses": [
        "Unit no. 25-30, First Floor, Idea Cosmic Plaza, Block C 2, Palam Vihar, Gurugram, Haryana 122017, India",
        "863/2, Ganga Vihar, Block A, Sector 12, Gurugram, Haryana 122001, India",
        "Unnamed Road, Block C, South City I, Sector 41, Gurugram, Haryana 122003, India"
    ],
    "origin_addresses": [
        "964, Block C 2, Sector 3, Gurugram, Haryana 122017, India"
    ],
    "rows": [
        
            "elements": [
                
                    "distance": 
                        "text": "0.2 km",
                        "value": 229
                    ,
                    "duration": 
                        "text": "1 min",
                        "value": 45
                    ,
                    "status": "OK"
                ,
                
                    "distance": 
                        "text": "4.1 km",
                        "value": 4094
                    ,
                    "duration": 
                        "text": "11 mins",
                        "value": 657
                    ,
                    "status": "OK"
                ,
                
                    "distance": 
                        "text": "9.1 km",
                        "value": 9092
                    ,
                    "duration": 
                        "text": "30 mins",
                        "value": 1791
                    ,
                    "status": "OK"
                
            ]
        
    ],
    "status": "OK"

APIClient 用于改造：

private static final String BASE_URL = "https://maps.googleapis.com/maps/";
    private static ApiClientMaps apiClient;
    private static Retrofit retrofit;

    private ApiClientMaps() 

        HttpLoggingInterceptor httpLoggingInterceptor= new HttpLoggingInterceptor();
        httpLoggingInterceptor.setLevel(HttpLoggingInterceptor.Level.BODY);
        OkHttpClient okHttpClient = new OkHttpClient.Builder().addInterceptor(httpLoggingInterceptor).build();

        Gson gson = new GsonBuilder()
                .setLenient()
                .create();


        retrofit = new Retrofit.Builder()
                .baseUrl(BASE_URL)
                .client(okHttpClient)
                .addConverterFactory(GsonConverterFactory.create(gson))
                .build();
    

    public static synchronized ApiClientMaps getInstance()
        if(apiClient == null)
            apiClient = new ApiClientMaps();
        
    return apiClient;
    

    public RetrofitMaps getApi()
        return retrofit.create(RetrofitMaps.class);
    

活动代码：

public class LocationFragment extends Fragment 

    String vehicleType, damagetype, brandname, modelname, makeyear, locationstr;
    private ListView listViewPlaces;
    List<Example> results ;


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) 
        View view = inflater.inflate(R.layout.fragment_location, container, false);

        vehicleType = getArguments().getString("vehicletype");
        damagetype = getArguments().getString("damagetype");
        brandname = getArguments().getString("brandname");
        modelname = getArguments().getString("modelname");
        makeyear = getArguments().getString("makeyear");
        locationstr = getArguments().getString("locationstr");

        listViewPlaces = view.findViewById(R.id.listViewPlaces);

        Getlist();

        return view;
    


    private void Getlist() 

        String units = "matric";
        String key = String.valueOf(R.string.google_maps_key);
        String destinations = "28.495430,77.020937";

        Call<List<Example>> call = ApiClientMaps.getInstance().getApi().getNearbyPlaces(units, String.valueOf(locationstr), destinations, key);
        call.enqueue(new Callback<List<Example>>() 
            @Override
            public void onResponse(Call<List<Example>> call, Response<List<Example>> response) 
                if (response.isSuccessful()) 
                    assert response.body() != null;

                    results=response.body();

                    PlacesListAdapter placesListAdapter = new PlacesListAdapter(getContext(), results);
                    listViewPlaces.setAdapter(placesListAdapter);

                 else 
                    Toast.makeText(getContext(), "Failed", Toast.LENGTH_LONG).show();
                
            

            @Override
            public void onFailure(Call<List<Example>> call, Throwable t) 
                Toast.makeText(getContext(), "Fail" + t.getMessage(), Toast.LENGTH_LONG).show();
            
        );
    

界面：

public interface RetrofitMaps 


    @POST("api/distancematrix/json")
    Call<List<Example>> getNearbyPlaces(
            @Query("units") String units,
            @Query("origins") String origin,
            @Query("destinations") String destination,
            @Query("key") String key);

主模型类：

例子：

public class Example 

    @SerializedName("destination_addresses")
    @Expose
    private List<String> destinationAddresses = null;
    @SerializedName("origin_addresses")
    @Expose
    private List<String> originAddresses = null;
    @SerializedName("rows")
    @Expose
    private List<Row> rows = null;
    @SerializedName("status")
    @Expose
    private String status;

    public Example() 
    

    public Example(List<String> destinationAddresses, List<String> originAddresses, List<Row> rows, String status) 
        super();
        this.destinationAddresses = destinationAddresses;
        this.originAddresses = originAddresses;
        this.rows = rows;
        this.status = status;
    

    public List<String> getDestinationAddresses() 
        return destinationAddresses;
    

    public void setDestinationAddresses(List<String> destinationAddresses) 
        this.destinationAddresses = destinationAddresses;
    

    public List<String> getOriginAddresses() 
        return originAddresses;
    

    public void setOriginAddresses(List<String> originAddresses) 
        this.originAddresses = originAddresses;
    

    public List<Row> getRows() 
        return rows;
    

    public void setRows(List<Row> rows) 
        this.rows = rows;
    

    public String getStatus() 
        return status;
    

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

行.java：

public class Row 

    @SerializedName("elements")
    @Expose
    private List<Element> elements = null;
    
    public Row(List<Element> elements) 
        super();
        this.elements = elements;
    

    public List<Element> getElements() 
        return elements;
    

    public void setElements(List<Element> elements) 
        this.elements = elements;
    

我想在列表视图中获取和存储数据，请帮助

【问题讨论】：

请发布原始模型类。

我已经发布了行模型类，请检查

这能回答你的问题吗？ Expected BEGIN_ARRAY but was BEGIN_OBJECT at line 1 column 2

不，我无法理解那个答案。

【参考方案1】：

尝试更改此设置

@POST("api/distancematrix/json")
Call<List<Example>> getNearbyPlaces(
        @Query("units") String units,
        @Query("origins") String origin,
        @Query("destinations") String destination,
        @Query("key") String key);

到

@POST("api/distancematrix/json")
Call<Example> getNearbyPlaces(
        @Query("units") String units,
        @Query("origins") String origin,
        @Query("destinations") String destination,
        @Query("key") String key);

以及与此相关的其他更改

因为您的响应是 JsonObject 而不是 JsonArray

【讨论】：

其实我之前试过了，响应是成功的，但是我无法将它存储到listview。

这可能是另一个问题。我已经为您在问题标题中提到的问题编写了解决方案

如何在列表视图中存储对象然后你能帮我吗？

如果您在显示列表视图时遇到问题，请相应地更改问题或使用与该问题相关的代码发布新问题。以便有人可以帮助您解决该特定问题

适配器期望列表，但响应作为对象返回，我该怎么办？