如何在java中读取json .txt文件[重复]

Question

我确信以前有人问过这个问题，但我确实需要帮助，因为我是 java 编程的书呆子（我真的很初学者）。 我使用 Netbeans 作为 IDE。 JSON文件有问题，我想解析它但不知道如何在java中解析。

这是我的 JSON 文件的样子：

    [
       {
          "rows":[
             {
                "positionId":1,
                "userName":"Abay Nurpeissov/ Абай Нурпеисов",
                "vacation":"",
                "position":"Student",
                "officePhone":"",
                "mobilePhone":"",
                "email":"",
                "userid":"201641686",
                "groupEmail":"",
                "departmentPathEN":""
             },
             {
                "positionId":1,
                "userName":"Abilmansur Yeshmuratov/ Абильмансур Ешмуратов",
                "vacation":"",
                "position":"Student",
                "officePhone":"",
                "mobilePhone":"",
                "email":"",
                "userid":"201551882",
                "groupEmail":"",
                "departmentPathEN":""
             }
                ]
      }
   ]

这是我的代码：

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package kyzdarkz;

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import org.apache.poi.hssf.usermodel.HSSFSheet;
/**
 *
 * @author anuar
 */
public class Kyzdarkz {

    //private ArrayList<Student> students = new ArrayList();

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) throws IOException {

        try(BufferedReader br = new BufferedReader(new FileReader("json.txt"))) {
            StringBuilder sb = new StringBuilder();
            String line = br.readLine();

        while (line != null) {
            sb.append(line);
            sb.append(System.lineSeparator());
            line = br.readLine();
        }
        String everything = sb.toString();
    }  

    }
}

我想将“userName”和“userid”保存为变量数组。我该怎么做？

Answer 1

1. 使用一些 Java 库：（例如：Gson、jackson）并将其导入您的项目中。

2. 创建一个对应输入json的类。例如：

   公共类 Emp {

   private String positionId;
   private String username;
   private String postion;
   
   //and so on ...
   
   public String getPositionId() {
       return positionId;
   }
   public void setPositionId(String positionId) {
       this.positionId = positionId;
   }
   public String getUsername() {
       return username;
   }
   public void setUsername(String username) {
       this.username = username;
   }
   public String getPostion() {
       return postion;
   }
   public void setPostion(String postion) {
       this.postion = postion;
   }
   
   //and so on ....
   

   }

3. 在你的方法中使用这个。

   Gson gson = new Gson();
   Emp[] person = gson.fromJson(input, Emp[].class);

查看这个深入的教程：http://www.java2blog.com/2013/11/gson-example-read-and-write-json.html