首页 > 解决方案 > 使用带有 JsonSyntaxException 的 Retrofit 在 Android 中解析 JSON

问题描述

我在这个“解析世界”中真的很新,我知道已经有很多关于这个问题的讨论(所以如果它可能是一个重复的问题,我很抱歉),但是,即使遵循一些指南并阅读一些答案,我找不到我的问题的解决方案。

我的错误是

Expected BEGIN_OBJECT but was STRING at line 1 column 1

我需要解析的JSON如下:

[ 
   { 
      "id":1,
      "name":"first",
      "filename":"36ba664b-769c-404f-87e2-4ee8b9ac20a2.png",
      "floor":3,
      "north":48.31202,
      "south":48.310677,
      "east":10.1578865,
      "west":10.155078,
      "opacity":1.0,
      "level":0
   },
   { 
      "id":2,
      "name":"second",
      "filename":"522f79d4-0dd4-4425-9f81-70a73bdfebc6.png",
      "floor":0,
      "north":48.31202,
      "south":48.310677,
      "east":10.1578865,
      "west":10.155078,
      "opacity":1.0,
      "level":0
   },
   { 
      "id":3,
      "name":"third",
      "filename":"00e10310-739a-407e-86b0-373ba71144e1.png",
      "floor":0,
      "north":53.02099,
      "south":53.02067,
      "east":-1.4836869,
      "west":-1.4843831,
      "opacity":1.0,
      "level":0
     }
]

所以,按照本指南:http ://www.androiddeft.com/retrofit-android/ 我创建了两个类:

数据和数据列表:

public class Data{

    @SerializedName("id")
    @Expose
    private Integer id;
    @SerializedName("name")
    @Expose
    private String name;
    @SerializedName("filename")
    @Expose
    private String filename;
    @SerializedName("floor")
    @Expose
    private Integer floor;
    @SerializedName("north")
    @Expose
    private Double north;
    @SerializedName("south")
    @Expose
    private Double south;
    @SerializedName("east")
    @Expose
    private Double east;
    @SerializedName("west")
    @Expose
    private Double west;
    @SerializedName("opacity")
    @Expose
    private Double opacity;
    @SerializedName("level")
    @Expose
    private Integer level;  
}

public class DataList{

    private ArrayList<Data> data = null;

    public ArrayList<Data> getData() {
        return data;
    }
}

在我创建了 API 服务和改造客户端之后:

public interface DataApiService {

    @GET("/")
    Call<DataList> getMyJSON();
}

public class DataRequestManager {

    private static String baseUrl = "mylink";

    private static Retrofit getRetrofitInstance() {

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

        HttpLoggingInterceptor logging = new HttpLoggingInterceptor();
        // set your desired log level
        if (BuildConfig.DEBUG) {
            logging.setLevel(HttpLoggingInterceptor.Level.BODY);
        } else {
            logging.setLevel(HttpLoggingInterceptor.Level.BASIC);
        }

        OkHttpClient.Builder httpClient = new OkHttpClient.Builder();
        httpClient.connectTimeout(10, TimeUnit.SECONDS);
        httpClient.readTimeout(20, TimeUnit.SECONDS);
        httpClient.writeTimeout(20, TimeUnit.SECONDS);
        httpClient.addInterceptor(logging);
        OkHttpClient debuggclient = httpClient.build();

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


        return retrofit;
    }

    public static DataApiService getApiService() {
        return getRetrofitInstance().create(DataApiService.class);
    }
}

但是当我这样做时:

        private static List<Data> dataList;

        DataApiService api = DataRequestManager.getApiService();

        Call<DataList> call = api.getMyJSON();

        call.enqueue(new Callback<DatasList>() {
            @Override
            public void onResponse(Call<DatasList> call, Response<DatasList> response) {

                if (response.isSuccessful()) {
                    //Got Successfully
                    dataList = response.body().getData();
                }
            }

            @Override
            public void onFailure(Call<DataList> call, Throwable t) {
                Toast.makeText(context, "Parsing Data Failed"+t.getMessage(),
                        Toast.LENGTH_LONG).show();
            }
        });

该应用程序给了我 JsonSyntaxEception:

com.google.gson.JsonSyntaxException: java.lang.IllegalStateException: 预期 BEGIN_OBJECT 但在第 1 行第 1 列路径 $

标签: androidgsonretrofitjsonparser

解决方案


你犯了一个非常基本的错误,你必须根据你的 json 更新你的界面:

public interface DataApiService {

    @GET("/")
    Call<List<Data>> getMyJSON();
}

您期待响应并像这样解析它:

{
  "data": [
    { .. }
  ]
}

但实际反应是这样的:

 [
    { .. }
 ]

更新:

在您的错误Expected BEGIN_ARRAY but was STRING at line 1 column 1中,显然意味着您收到如下响应:

"[

  {
    ...
  }

 ]"

而不是这个:

 [

      {
        ...
      }

]

我已将您的 Json 粘贴到编辑器中:

在此处输入图像描述

正如您在左下角Ln: 1 Col: 1看到的那样,在 Json 的开头看到光标在这里[,您会收到错误,因为您期望像数组一样[{...}]但实际响应是"[{...}]"

只是为了证明我的观点,像这样更新你的界面:

public interface DataApiService {

    @GET("/")
    Call<String> getMyJSON();
}

你不会得到错误。

更多信息可以在这里找到


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