java - 如何提取我的 simplejson 数组的数据？

Question

我想提取 JSONArray 对象的所有注释，我发现了这篇文章 https://www.mkyong.com/java/json-simple-example-read-and-write-json/ 。问题是我的 JSONArray 是一种“数组的数组”:

[{"AnnotationOfzelda":
 [{"annotation":
  [{"duration":5000,"annotation":"salut","timestamp":2250.0}, 
   {"duration":5000,"annotation":"jp","timestamp":4570.0}]}, 
   {"duration":5000,"annotation":"asd","timestamp":3340.0}, 
   {"duration":5000,"annotation":"asd","timestamp":4040.0}]}]

我尝试了这段代码(来 self 链接的帖子)

 System.out.println(annotationJSON.toJSONString());

 Iterator<JSONObject> iterator = annotationJSON.iterator();
 while (iterator.hasNext()) {
  JSONObject factObj = (JSONObject) iterator.next();
  String annotation = (String) factObj.get("annotation");
  System.out.println(annotation);
 }

结果是“null”，我认为这是因为我需要进入数组“annotation”，而目前我只在“AnnotationOfzelda”中

Answer 1

尝试一下，您可以将其用于 JSON 中的特定值(注释:“asd”)或完整的 JSON:

import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;

import java.io.IOException;
import java.util.Iterator;

public class Sol {
    public static void main(String[] args) {
        String data = "[{\"AnnotationOfzelda\":\n" +
                " [{\"annotation\":\n" +
                "  [{\"duration\":5000,\"annotation\":\"salut\",\"timestamp\":2250.0}, \n" +
                "   {\"duration\":5000,\"annotation\":\"jp\",\"timestamp\":4570.0}]}, \n" +
                "   {\"duration\":5000,\"annotation\":\"asd\",\"timestamp\":3340.0}, \n" +
                "   {\"duration\":5000,\"annotation\":\"asd\",\"timestamp\":4040.0}]}]";
        ObjectMapper objectMapper = new ObjectMapper();
        JsonNode jsonNode = null;
        try {
            jsonNode = objectMapper.readTree(data);
            Iterator iterator = jsonNode.iterator();
            while (iterator.hasNext()) {
                JsonNode node = (JsonNode) iterator.next();
                if (node.get("annotation") != null) {
                    System.out.println(node.get("annotation"));
                    continue;
                }
                if (node.iterator().hasNext()) {
                    iterator = node.iterator();
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

输出[{"duration":5000,"annotation":"salut","timestamp":2250.0},{"duration":5000,"annotation":"jp","timestamp":4570.0}]“自闭症谱系障碍”“阿斯德”