Java中的JSON数组

Question

因此，我希望在一个允许http post请求的组消息应用程序中添加许多用户，我将尝试使用文件上传功能从JSON中读取数据，但对于如何用java编写该应用程序，我感到有点困惑：

{
  "members": [
    {
      "nickname": "Mom",
      "user_id": "1234567890",
      "guid": "GUID-1"
    },
    {
      "nickname": "Dad",
      "phone_number": "+1 2123001234",
      "guid": "GUID-2"
    },
    {
      "nickname": "Jane",
      "email": "jane@example.com",
      "guid": "GUID-3"
    }
  ]
}

这是我需要写入的JSON文件的一个示例，有人能解释一下如何用Java编写吗？(它需要昵称& phone_number字段，只有这两个人)谢谢！

编辑1:对不起，不清楚。我需要使用Java生成一个包含这些内容的文件。

Answer 1

试着试试https://github.com/google/gson

http://www.studytrails.com/java/json/java-google-json-parse-json-to-java.jsp

示例：

import com.google.gson.Gson;

public class JavaToJsonAndBack {

    public static void main(String[] args) {
        Albums albums = new Albums();
        albums.title = "Free Music Archive - Albums";
        albums.message = "";
        albums.total = "11259";
        albums.total_pages = 2252;
        albums.page = 1;
        albums.limit = "5";
        GsonBuilder builder = new GsonBuilder();
        Gson gson = builder.create();
        System.out.println(gson.toJson(albums));

    }
}

This is how the resulting JSON looks like

{"title":"Free Music Archive - Albums","message":"","errors":[],
"total":"11259","total_pages":2252,"page":1,"limit":"5"}

Answer 2

将{}视为类，将[]视为数组：

import com.google.gson.annotations.SerializedName;

public class Message {
    @SerializedName("members")
    private List<Member> members;
...

public class Member {
    @SerializedName("nickname")
    private String nickname;
    @SerializedName("user_id")
    private String userId;
    @SerializedName("guid")
    private String guid;
...

要转换为JSON，请执行以下操作：

Message msg;
...
String jsonResult = new Gson().toJson(msg);

要从JSON返回：

Message msg = new Gson().fromJson(jsonStr, Message.class);

用户指南：https://sites.google.com/site/gson/gson-user-guide