java - 在 JAVA 中的特定位置写入 JSON 文件

Question

我需要一点帮助(如果这是一个愚蠢的问题，我很抱歉，但我是初学者，我曾多次尝试解决我的问题但没有成功......)

例如，我想在 JSON 文件中的特定位置写入，为 Sarah 添加新分数(id 2)

[
{"id":1,"name":"Josh","score":["100","150","50"]},
{"id":2,"name":"Sarah","score":["150","200","200"]},
{"id":3,"name":"Thomas","score":["10","100","150"]},
]

到

[
{"id":1,"name":"Josh","score":["100","150","50"]},
{"id":2,"name":"Sarah","score":["150","200","200","300"]},
{"id":3,"name":"Thomas","score":["10","100","150"]},
]

Answer 1

导入类:

import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;

import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;

从 json 文件中读取所有 Json 对象:

    JSONParser jsonParser = new JSONParser();

    try (FileReader reader = new FileReader("sample.json"))
    {
        //Read JSON file
        Object obj = jsonParser.parse(reader);
        JSONArray list= (JSONArray) obj;  

    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    } catch (ParseException e) {
        e.printStackTrace();
    }

现在通过迭代在列表中进行修改:

int count = list.length(); // get totalCount of all jsonObjects
            for(int i=0 ; i< count; i++){   // iterate through jsonArray 
                JSONObject jsonObject = list.getJSONObject(i);  // get jsonObject @ i position 
            }

在json文件中再次写入:

  try (FileWriter file = new FileWriter("sample.json")) {
        file.write(list.toJSONString());
        file.flush();

    } catch (IOException e) {
        e.printStackTrace();
    }