使用Java和Jackson将数组写入JSON

我需要通过从csv读取来创建一个类似这样的JSON结构

[
  {
    "firstName": "John",
    "lastName": "Smith",
    "udas": [
      {
        "name": "UDF1",
        "dataType": "number",
        "value": 0
      }
    ]
  }
]

我得到的结构是

[{
    "firstName": "Michael",
    "lastName": "Dodd"
}, {
    "udas": [{
        "name": "UDF1",
        "dataType": "number",
        "entityCode": 0
    }]
}]

读取文件没有问题，但是格式化JSON是一个问题。如何去掉“udas”数组周围多余的花括号

这是我正在使用的代码

public class MyTestClass {
    public static void main(String[] args) {
        String row;
        String[] data = {};
        ObjectMapper objectMapper = new ObjectMapper();      

        try {
            BufferedReader csvReader = new BufferedReader(new FileReader("res/mydata.csv"));
            row = csvReader.readLine();
            data = row.split(",");

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

        ArrayNode arrayNode = objectMapper.createArrayNode();

        ObjectNode personObjectNode = objectMapper.createObjectNode();
        personObjectNode.put("firstName", data[0]);
        personObjectNode.put("lastName", data[1]);
        arrayNode.add(personObjectNode);

        ArrayNode udaArrayNode = objectMapper.createArrayNode();

        ObjectNode approvalAuthorityObjectNode = objectMapper.createObjectNode();
        approvalAuthorityObjectNode.put("name", "UDF1");
        approvalAuthorityObjectNode.put("dataType", "number");
        approvalAuthorityObjectNode.put("entityCode", Integer.parseInt(data[15]));
        udaArrayNode.add(approvalAuthorityObjectNode);

        ObjectNode udaObjectNode = objectMapper.createObjectNode();        
        udaObjectNode.putPOJO("udas", udaArrayNode);
        arrayNode.add(udaObjectNode);

        System.out.println(arrayNode.toString());    
    }
}

---

以下更改修复了该问题。谢谢，@SotiriosDelimanolis

public class MyTestClass{
    public static void main(String[] args) {
        String row;
        String[] data = {};
        ObjectMapper objectMapper = new ObjectMapper();      

        try {
            BufferedReader csvReader = new BufferedReader(new FileReader("res/mydata.csv"));
            row = csvReader.readLine();
            data = row.split(",");

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

        ArrayNode arrayNode = objectMapper.createArrayNode();

        ObjectNode personObjectNode = objectMapper.createObjectNode();
        personObjectNode.put("firstName", data[0]);
        personObjectNode.put("lastName", data[1]);
        arrayNode.add(personObjectNode);

        ArrayNode udaArrayNode = objectMapper.createArrayNode();
        ObjectNode approvalAuthorityObjectNode = objectMapper.createObjectNode();
        approvalAuthorityObjectNode.put("name", "UDF1");
        approvalAuthorityObjectNode.put("dataType", "number");
        approvalAuthorityObjectNode.put("entityCode", Integer.parseInt(data[15]));

        udaArrayNode.add(approvalAuthorityObjectNode);

        personObjectNode.putPOJO("udas", udaArrayNode);

        System.out.println(arrayNode.toString());    
    }
}

现在我得到了JSON

[{
    "firstName": "Michael",
    "lastName": "Dodd",
    "udas": [{
        "name": "UDF1",
        "dataType": "number",
        "entityCode": 0
    }]
}]

---

为什么要将

uda

添加到新的

ObjectNode

，并将其添加到

arrayNode

？您应该将其添加到

PersonObject节点

。我不确定是否遵循了此操作。是

ObjectNode UDAOObjectNode=objectMapper.createObjectNode（）您所指的语句？如果我更改
arrayNode.add（udaObjectNode）
到
arrayNode.add（udaObjectNode）我得到了一个JSON，它只复制了第一部分
[{“firstName”：“Michael”，“lastName”：“Dodd”}，{“firstName”：“Michael”，“lastName”：“Dodd”}]
。去掉代码的整个
udaObjectNode
部分，只需
personObjectNode.putPOJO（“udas”，udaArrayNode）。