嵌套的JSON解析与杰克逊的Andr​​oid [英] nested json parsing for android with jackson

问题描述

我刚开始到Android prograamming，并通过使用IMDB API找到很好的教程。而不是在本教程中使用的XML我想用JSON并为recevied JSON我有一个问题。
这是person.json：

i just started to android prograamming and found nice tutorial by using imdb api. instead of using xml in this tutorial i would like to use json and for the recevied json i have a problem. this is the person.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"
}
]

我的两个对象，为他们：

my two object for them:

    public class Person implements Serializable {

   private static final long serialVersionUID = 6794898677027141412L;

   public String score;
   public String popularity;
   public String name;
   public String id;
   public String biography;
   public String url;
   public String version;
   public String lastModifiedAt;
   public Profile profile;
    }

    public class Profile implements Serializable {

   private static final long serialVersionUID = -8735669377345509929L;

   public ArrayList<Image> imagesList;

    }

    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;   
    }

我不能想出如何利用杰克逊对象映射器检索人员列表。
当我使用这一个：

ı couldnt figure out how to retrieve person list by using jackson object mapper. when i use this one:

    ObjectMapper mapper = new ObjectMapper();
    Person person= mapper.readValue(jsonResponseString, Person.class);

我得到：

18 02-16：34：48.010：W / System.err的（376）：com.fasterxml.jackson.databind.JsonMappingException：无法反序列化com.example.imdbsearcher.model.Person实例出来START_ARRAY令牌
02-16 18：34：48.180：W / System.err的（376）：在[来源：java.io.StringReader@40a81778;行：1，柱：1]
02-16 18：34：48.554：W / System.err的（376）：在com.fasterxml.jackson.databind.DeserializationContext.mappingException(DeserializationContext.java:599)
02-16 18：34：48.830：W / System.err的（376）：在com.fasterxml.jackson.databind.DeserializationContext.mappingException(DeserializationContext.java:593)

02-16 18:34:48.010: W/System.err(376): com.fasterxml.jackson.databind.JsonMappingException: Can not deserialize instance of com.example.imdbsearcher.model.Person out of START_ARRAY token 02-16 18:34:48.180: W/System.err(376): at [Source: java.io.StringReader@40a81778; line: 1, column: 1] 02-16 18:34:48.554: W/System.err(376): at com.fasterxml.jackson.databind.DeserializationContext.mappingException(DeserializationContext.java:599) 02-16 18:34:48.830: W/System.err(376): at com.fasterxml.jackson.databind.DeserializationContext.mappingException(DeserializationContext.java:593)

我已经改变了与Keith和crdnilfan的意见检索方法。
但现在我有轮廓的属性问题。

i have changed the retrieve method with advice of Keith and crdnilfan. but now i have a problem with the attribute of profile.

我意识到，我很想念一个人，在对象basicly我已经创造了新的配置文件对象和移动图像列表此类。

i realized that i am missing that one in person object and basicly i have created new profile object and moved imageList to this class.

我已经更新POJO的方法同上。

i have updated POJO's as above.

但现在我得到同样的错误的配置文件。

but now i am getting the same error for the profile.

无法反序列化com.example.imdbsearcher.model.Profile实例出来START_ARRAY令牌

Can not deserialize instance of com.example.imdbsearcher.model.Profile out of START_ARRAY token

推荐答案

您需要反序列化的列表，你JSON是一个数组：

You need to deserialize the list, as your JSON is an array:

List<Person> people = mapper.readValue(
                      jsonResponseString, new TypeReference<List<Person >>(){});

然而，在你做，你将不得不因为在你的JSON配置文件属性的一些额外的反序列化的错误。结帐：<一href=\"http://jackson.$c$chaus.org/1.5.7/javadoc/org/$c$chaus/jackson/annotate/JsonIgnoreProperties.html\" rel=\"nofollow\">http://jackson.$c$chaus.org/1.5.7/javadoc/org/$c$chaus/jackson/annotate/JsonIgnoreProperties.html

更新：

public class Person implements Serializable 
{

  public List<Object> profile;

  public String score;
  public String popularity;
  public String name;
  public String id;
  public String biography;
  public String url;
  public String version;
  public String last_modified_at;
}

有几种方法来处理这​​个问题。这会给你的个人资料链接的哈希映射。

There are several ways to deal with this. This will give you a linked hash map for Profile.

另外，如果你控制了JSON格式，配置文件的语法改成这样：

Alternatively, if you control the JSON format, change the profile syntax to this:

"profile":[
      image:...,
      image:...
 ]

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