Question

我是JSON的新手，并且在为后续JSON输入创建POJO时遇到问题。

    [
    {
"score":1,
"popularity":3,
"name":"Brad Pitt",
"id":287,
"biography":"test",
"url":"http://www.themoviedb.org/person/287",
"profile":[
    {
        "image":{
            "type":"profile",
            "size":"thumb",
            "height":68,
            "width":45,
            "url":"http://d3gtl9l2a4fn1j.cloudfront.net/t/p/w45/w8zJQuN7tzlm6FY9mfGKihxp3Cb.jpg",
            "id":"4ea5cb8c2c0588394800006f"
        }
    },
    {
        "image":{
            "type":"profile",
            "size":"profile",
            "height":281,
            "width":185,
            "url":"http://d3gtl9l2a4fn1j.cloudfront.net/t/p/w185/w8zJQuN7tzlm6FY9mfGKihxp3Cb.jpg",
            "id":"4ea5cb8c2c0588394800006f"
        }
    },
    {
        "image":{
            "type":"profile",
            "size":"h632",
            "height":632,
            "width":416,
            "url":"http://d3gtl9l2a4fn1j.cloudfront.net/t/p/h632/w8zJQuN7tzlm6FY9mfGKihxp3Cb.jpg",
            "id":"4ea5cb8c2c0588394800006f"
        }
    },
    {
        "image":{
            "type":"profile",
            "size":"original",
            "height":1969,
            "width":1295,
            "url":"http://d3gtl9l2a4fn1j.cloudfront.net/t/p/original/w8zJQuN7tzlm6FY9mfGKihxp3Cb.jpg",
            "id":"4ea5cb8c2c0588394800006f"
        }
    }
],
"version":685,
"last_modified_at":"2013-02-16 07:11:15 UTC"
  }
  ]

我创建了三个POJO，其中一个是主要的人类，这个也包含个人资料对象。配置文件对象返回图像列表。：

    public class Person implements Serializable {

  private static final long serialVersionUID = 6794898677027141412L;

  public String biography;
  public String id;
  public String last_modified_at;
  public String name;
  public String popularity;
  public String score;
  public String url;
  public String version;
  public ArrayList<Profile> profile;

  //getters and setters
    }

    public class Profile implements Serializable {

  private static final long serialVersionUID = -6482559829789740926L;

  public ArrayList<Image> image;

    }


    public class Image implements Serializable {

    private static final long serialVersionUID = -2428562977284114465L;

    public String type;
    public String url;
    public String size;
    public int width;
    public int height;
    }

检索我正在使用gson的数据：

  Gson gson = new Gson();
  Type collectionType = new TypeToken<List<Person>>(){}.getType();
  List<Person> details = gson.fromJson(json, collectionType);

当我运行时，我得到了：

  02-17 11:04:50.531: E/AndroidRuntime(405): Caused by:  com.google.gson.JsonSyntaxException: java.lang.IllegalStateException: Expected BEGIN_ARRAY but was BEGIN_OBJECT at line 1 column 3

更新了图片POJO：

public class Image implements Serializable {

private static final long serialVersionUID = -2428562977284114465L;
private Object image;

public class ImageInner {

    public static final String SIZE_ORIGINAL = "original";
    public static final String SIZE_MID = "mid";
    public static final String SIZE_COVER = "cover";
    public static final String SIZE_THUMB = "thumb";
    public static final String TYPE_PROFILE = "profile";
    public static final String TYPE_POSTER = "poster";
    public String type;
    public String url;
    public String size;
    public int width;
    public int height;

}
}

谢谢

Answer 1

您的代码实际上真的关闭，有两个错误：

1）您收到的错误告诉您，在JSON的最开始，它期待数组的开始（[），但得到了一个对象的开始（{{1}相反。您发布的JSON是而不是您正在为Gson提供什么（见下文）。

2）当您更正上述内容时，{ POJO中存在一个小问题：

Person

应该是：

public ArrayList<Profile> profile;

你实际上不需要你的public ArrayList<Image> profile;课程; JSON 中的Profile是数组。你会收到另一个类似于你现在收到的错误，因为它会期待一个profile个对象的ArrayList：Profile

如果您修复了第二个并为Gson提供了您发布的JSON，那么它的效果非常好。您已经发布了一组"profile":[{"image":[{imageobject},...]},{"image":[{imageobject},...]}]个对象，但您在代码中实际拥有的内容（在Person中）只是一个对象...或包含您发布的数组的对象。下面的小例子非常有效（在纠正你的json课程后）：

Person

编辑添加：您实际上正在进行一些Gson正在为您处理的类型转换......但您可能并不真正想要。例如，在您的JSON中public class App { static String json = "[{\"score\":1,\"popularity\":3,\"name\":\"Brad Pitt\",\"id\":287," + "\"biography\":\"test\",\"url\":\"http://www.themoviedb.org/person/287\",\"profile\":" + "[{\"image\":{\"type\":\"profile\",\"size\":\"thumb\",\"height\":68,\"width\":45,\"url\":" + "\"http://d3gtl9l2a4fn1j.cloudfront.net/t/p/w45/w8zJQuN7tzlm6FY9mfGKihxp3Cb.jpg\"," + "\"id\":\"4ea5cb8c2c0588394800006f\"}},{\"image\":{\"type\":\"profile\",\"size\":\"profile\"," + "\"height\":281,\"width\":185,\"url\":\"http://d3gtl9l2a4fn1j.cloudfront.net/t/p/w185/w8zJQuN7tzlm6FY9mfGKihxp3Cb.jpg\"," + "\"id\":\"4ea5cb8c2c0588394800006f\"}},{\"image\":{\"type\":\"profile\",\"size\":\"h632\",\"height\":632,\"width\":416,"+ "\"url\":\"http://d3gtl9l2a4fn1j.cloudfront.net/t/p/h632/w8zJQuN7tzlm6FY9mfGKihxp3Cb.jpg\"," + "\"id\":\"4ea5cb8c2c0588394800006f\"}},{\"image\":{\"type\":\"profile\",\"size\":\"original\",\"height\":1969," + "\"width\":1295,\"url\":\"http://d3gtl9l2a4fn1j.cloudfront.net/t/p/original/w8zJQuN7tzlm6FY9mfGKihxp3Cb.jpg\"," + "\"id\":\"4ea5cb8c2c0588394800006f\"}}],\"version\":685,\"last_modified_at\":\"2013-02-16 07:11:15 UTC\"" + "}]"; public static void main(String[] args) { Gson gson = new Gson(); Type collectionType = new TypeToken<List<Person>>(){}.getType(); List<Person> details = gson.fromJson(json, collectionType); } }是score，但在您的POJO中，您已将其设为int。 Gson默默地进行转换。

另外，像我上面所做的那样简单地创建SSCCE（http://sscce.org/）可以帮助您调试这些问题。

POJO用于嵌套json

1 个答案:

POJO用于​​嵌套json

1 个答案:

POJO用于嵌套json