Question

我试图将这个json bellow解析为一个名为AlbumResponse的对象，其中包含另外两个对象Album和PaginationInfo。改造版本2.0

[
    {
        "id": "6",
        "name": "King Stays King",
        "artist_name":"Timbaland",
        "image":""
    },
    {
        "id": "7",
        "name": "East Atlanta Santa 2",
        "artist_name":"Gucci Mane",
        "image":""
    },
    {
        "id": "8",
        "name": "The cuban connect",
        "artist_name":"Phophit",
        "image":""
    },
    {
        "id": "9",
        "name": "Shmoney Keeps",
        "artist_name":"Calling",
        "image":""
    },
    {
        "id": "10",
        "name": "Cabin Fever 3",
        "artist_name":"Wiz khalifa",
        "image":""
    }
],
{
    "nextPage": "http://private-ede172-mymixtapez1.apiary-mock.com/features/page_3/",
    "itemsTotal": 10,
    "page": 2,
    "pagerMax": 2
}

专辑类

public class Album {
    long id;
    String name;
    @SerializedName("artist_name")
    String artistName;
    String image;
}

PaginationInfo类

public class PaginationInfo {
    int page;
    int pagerMax;
    int nextPage;
    int itemsTotal;
}

AlbumResponse，上面有两个类，Album是List

public class AlbumResponse {
    public List<Album> albums;
    public PaginationInfo paginationInfo;
}

请求

Call<AlbumResponse> responseCall = albumService.features();
responseCall.enqueue(new Callback<AlbumResponse>() {
    @Override
    public void onResponse(Response<AlbumResponse> response, Retrofit retrofit) {
        if(response.isSuccess()) {
            AlbumResponse albumResponse = response.body();
            PaginationInfo paginationInfo = albumResponse.getPaginationInfo();

        }
        System.out.println();
    }

    @Override
    public void onFailure(Throwable t) {
        System.out.println(t.getMessage());
    }
});

接口

public interface AlbumService {
  @GET("/features/")
  Call<AlbumResponse> features();
}

问题是我得到的Throwable包含：

com.google.gson.JsonSyntaxException：java.lang.IllegalStateException：预期为BEGIN_OBJECT，但在第1行第2列路径为BEGIN_ARRAY $`

请有人帮助我，我在stackoverflow中找不到任何答案。感谢。

Answer 1

错误说：Parser期望一个JSON-Object，但它读取一个JSON数组。要修复它（如果您控制服务器），您应该将JSON字符串更改为以下内容：

{
  "albums" : [
    {
        "id": "6",
        "name": "King Stays King",
        "artist_name":"Timbaland",
        "image":""
    },
    {
        "id": "7",
        "name": "East Atlanta Santa 2",
        "artist_name":"Gucci Mane",
        "image":""
    },
    {
        "id": "8",
        "name": "The cuban connect",
        "artist_name":"Phophit",
        "image":""
    },
    {
        "id": "9",
        "name": "Shmoney Keeps",
        "artist_name":"Calling",
        "image":""
    },
    {
        "id": "10",
        "name": "Cabin Fever 3",
        "artist_name":"Wiz khalifa",
        "image":""
    }
],
 "paginationInfo" : {
    "nextPage": "http://private-ede172-mymixtapez1.apiary-mock.com/features/page_3/",
    "itemsTotal": 10,
    "page": 2,
    "pagerMax": 2
 }
}

现在它是一个JSON-Object并且符合你的Java类。

如果您无法更改后端的JSON，我会将其作为行响应并使用GSON或手动分别解析albums Array和PaginationInfo。

顺便说一下。您必须在nextPage类

中将int类型从String更改为PaginationInfo

Answer 2

您的JSON在初始声明中遇到了麻烦。

根据json.org：

JSON基于两种结构：

•名称/值对的集合。在各种语言中，这是   实现为对象，记录，结构，字典，哈希表，键控   列表或关联数组。

•有序的值列表。多数情况   语言，这被实现为数组，向量，列表或序列。

尝试将您的JSON更新为：

"albums": [
    {
        "id": "6",
        "name": "King Stays King",
        "artist_name":"Timbaland",
        "image":""
    },
    {
        "id": "7",
        "name": "East Atlanta Santa 2",
        "artist_name":"Gucci Mane",
        "image":""
    },
    {
        "id": "8",
        "name": "The cuban connect",
        "artist_name":"Phophit",
        "image":""
    },
    {
        "id": "9",
        "name": "Shmoney Keeps",
        "artist_name":"Calling",
        "image":""
    },
    {
        "id": "10",
        "name": "Cabin Fever 3",
        "artist_name":"Wiz khalifa",
        "image":""
    }
],
"pagination_info": 
{
    "nextPage": "http://private-ede172-mymixtapez1.apiary-mock.com/features/page_3/",
    "itemsTotal": 10,
    "page": 2,
    "pagerMax": 2
}

在改造2.0中无法用两种不同的数据类型解析json

2 个答案: