JSON GSON.fromJson Java对象 [英] JSON GSON.fromJson Java Objects

问题描述

我试图将我的Json加载到我的类中

$ b

  public User（）{
 this.fbId = 0; 
 this.email =; 
 this.name =; 
 this.thumb =; 
 this.gender =; 
 this.location =; 
 this.relationship = null; 
 this.friends = new ArrayList（）; 
 
  

  {
用户：{
用户：{
名称：'姓名'，
电子邮件：'[e-mail]'，
朋友：{
用户：{
名称：'别名'，
电子邮件地址：'[e-mail]'，
朋友：{
用户：{
名称：'又一个名字'，
 email：'[e-mail]'
} 
} 
} 
} 
} 
} 
 
 
 
 $ b $ p 
 $ b我很努力让GSON将用户细节加载到上面的Java对象中以下代码
  User user = gson.fromJson（this.json，User.class）; 
  
 
 
解决方案
 JSON无效。集合不能由 {} 表示。它代表一个对象。集合/数组将由 [] 和逗号分隔的对象表示。
 
 
 
以下是JSON的外观： 
 
 
  {
 users：[{
 name：name1，
 email： email1，
朋友：[{
 name：name2，
 email：email2，
 friends：[{
 name：name3， 
 email：email3
}，
 {
 name：name4，
 email：email4
}] 
} ] 
}] 
} 
  
 更深的嵌套好友的朋友，以便您了解如何在集合中指定多个对象） 
 
 
 
鉴于此JSON，您的包装类应该看起来像这： 
 
 
  public class Data {
 private List< User>用户; 
 // + getters / setters 
} 
 
 public class User {
 private String name; 
私人字符串电子邮件; 
私人列表<用户>朋友; 
 // + getters / setters 
} 
  
然后转换它，使用
 数据数据= gson.fromJson（this.json，Data.class）; 
  
并获取用户，请使用 
 
 
 列表<使用者> users = data.getUsers（）; 
  
 
I am trying to load my Json into my class
public User() {
    this.fbId = 0;
    this.email = "";
    this.name = "";
    this.thumb = "";
    this.gender = "";
    this.location = "";
    this.relationship = null;
    this.friends = new ArrayList();
}


{
    users:{
        user:{
            name:'the name',
            email:'[e-mail]',
            friends:{
                user:{
                    name:'another name',
                    email:'[e-mail]',
                    friends:{
                        user:{
                            name:'yet another name',
                            email:'[e-mail]'
                        }
                    }
                }
            }
        }
    }
}
I am struggling to get GSON to load the user details into the above Java object with the following code
User user = gson.fromJson(this.json, User.class);

解决方案
The JSON is invalid. A collection is not to be represented by {}. It stands for an object. A collection/array is to be represented by [] with commaseparated objects.


Here's how the JSON should look like:
{
    users:[{
        name: "name1",
        email: "email1",
        friends:[{
            name: "name2",
            email: "email2",
            friends:[{
                name: "name3",
                email: "email3"
            },
            {
                name: "name4",
                email: "email4"
            }]
        }]
    }]
}
(note that I added one more friend to the deepest nested friend, so that you understand how to specify multiple objects in a collection)

Given this JSON, your wrapper class should look like this:
public class Data {
    private List<User> users;
    // +getters/setters
}

public class User {
    private String name;
    private String email;
    private List<User> friends;
    // +getters/setters
}
and then to convert it, use
Data data = gson.fromJson(this.json, Data.class);
and to get the users, use
List<User> users = data.getUsers();


                        
这篇关于JSON GSON.fromJson Java对象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！