使用Gson将Json对象解析为Json数组 [英] Parsing Json Object to Json Array using Gson

问题描述

  {
discussion：[{ 
id：54，
name：Test Discusssion，
讨论：41，
创建：1472816138，
modified ：1472816138，
subject：Test Discusssion，
message：< p>欢迎所有人参加测试讨论< \ / p>，
}]，
warnings：[] 
} 
  

但是我在解析它as

  ArrayList< MoodleDiscussion> mDiscussions = gson.fromJson（阅读器，
新TypeToken< List< MoodleDiscussion>>（）{
} .getType（））; 
  

我得到的错误是

java.lang.IllegalStateException：预期的BEGIN_ARRAY，但是BEGIN_OBJECT

我想将接收到的json转换为数组， p>

以下是MoodleDiscussion类

  public class MoodleDiscussion extends SugarRecord< Moodle讨论> {@ 
 SerializedName（id）int discussionid; @ 
 SerializedName（name）字符串名称; @ 
 SerializedName（subject）String subject; 
 public int getDiscussionid（）{
 return discussionid; 
} 
 public String getName（）{
 return name; 
} 
 public int getUserid（）{
 return userid; 
} 
 public String getSubject（）{
 return subject; 
} 
} 
  

解决方案

你要解析的列表包含在一个嵌套的JSON数据结构中，如果Gson要解析它，它也需要在Java类中表示。

你会需要一个类似如下的容器类：

  public class MoodleDiscussionResponse {
 private List< MoodleDiscussion>讨论; 
私人列表< Object>警告; 
 
公开列表< MoodleDiscussion> getDiscussions（）{
返回讨论; 
} 
 
 public List< Object> getWarnings（）{
返回警告; 
} 
} 
  

然后您应该可以像这样读取它：

  MoodleDiscussionResponse response = gson.fromJson（reader，MoodleDiscussionResponse.class）; 
列表< MoodleDiscussion> mDiscussions = response.getDiscussions（）; 
  

I am calling a webservice which gives me a json like this

{
    "discussions": [{
        "id": 54,
        "name": "Test Discusssion",
        "discussion": 41,
        "created": 1472816138,
        "modified": 1472816138,
        "subject": "Test Discusssion",
        "message": "<p>Welcome all to test discussion<\/p>",
    }],
    "warnings": []
}

But in android I am parsing it as

ArrayList<MoodleDiscussion> mDiscussions = gson.fromJson(reader,
      new TypeToken<List<MoodleDiscussion>>() {
      }.getType());

And the error I am getting is

java.lang.IllegalStateException: Expected BEGIN_ARRAY but was BEGIN_OBJECT

I want to convert the received json into an array how should I ?

Here is the MoodleDiscussion class

public class MoodleDiscussion extends SugarRecord < MoodleDiscussion > {@
    SerializedName("id") int discussionid;@
    SerializedName("name") String name;@
    SerializedName("subject") String subject;
    public int getDiscussionid() {
        return discussionid;
    }
    public String getName() {
        return name;
    }
    public int getUserid() {
        return userid;
    }
    public String getSubject() {
        return subject;
    }
}

解决方案

The list you're trying to parse is contained within a nested json data structure that also needs to be represented in java classes if Gson is to parse it correctly.

You'll need a container class that looks something like this:

public class MoodleDiscussionResponse {
    private List<MoodleDiscussion> discussions;
    private List<Object> warnings;

    public List<MoodleDiscussion> getDiscussions() {
        return discussions;
    }

    public List<Object> getWarnings() {
        return warnings;
    }
}

Then you should be able to read it like so:

MoodleDiscussionResponse response = gson.fromJson(reader, MoodleDiscussionResponse.class);
List<MoodleDiscussion> mDiscussions = response.getDiscussions(); 

这篇关于使用Gson将Json对象解析为Json数组的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！