JSON数据节点遍历：使用JSON.simple进行结构化与通用解析

{
    "message": "Results field contain api response",
    "results": {
        "Person 1": "USA",
        "Person 2": "India",
        "Name 3": "Europe",
        "People": "Germany"
    }
}

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

import java.io.FileReader;
import java.io.IOException;
import java.io.Reader;

public class JsonNodeTraversalExample {
    public static void main(String[] args) {
        // 假设JSON内容存储在名为 "test.json" 的文件中
        // 实际应用中可以是字符串、网络流等
        String jsonFilePath = "/tmp/test.json"; // 请替换为你的JSON文件路径

        try (Reader reader = new FileReader(jsonFilePath)) {
            // 1. 创建JSONParser实例并解析JSON文件
            JSONParser parser = new JSONParser();
            JSONObject root = (JSONObject) parser.parse(reader);

            // 2. 访问顶层字段 "message"
            String message = (String) root.get("message");
            System.out.println("Message: " + message);

            // 3. 访问嵌套的 "results" 对象
            JSONObject results = (JSONObject) root.get("results");

            // 4. 遍历 "results" 对象中的所有键值对
            if (results != null) {
                // results.keySet() 返回 Set<Object>，需要进行类型转换
                for (Object keyObj : results.keySet()) {
                    String key = (String) keyObj; // 假定键为字符串
                    Object value = results.get(key);
                    System.out.println(key + ": " + value);
                }
            } else {
                System.out.println("Results field is null or not found.");
            }

        } catch (IOException e) {
            System.err.println("文件读取错误: " + e.getMessage());
            throw new RuntimeException("无法读取JSON文件", e);
        } catch (ParseException e) {
            System.err.println("JSON解析错误: " + e.getMessage());
            throw new RuntimeException("JSON数据格式不正确", e);
        } catch (ClassCastException e) {
            System.err.println("JSON节点类型转换错误，请检查JSON结构: " + e.getMessage());
            throw new RuntimeException("JSON结构与预期不符，请检查强制类型转换", e);
        }
    }
}

Message: Results field contain api response
Person 1: USA
Person 2: India
People: Germany
Name 3: Europe

function traverseJsonNode(node):
    if node is JSONObject:
        for each key-value pair in node:
            print "Key:", key
            traverseJsonNode(value) // 递归调用处理值
    else if node is JSONArray:
        for each element in node:
            traverseJsonNode(element) // 递归调用处理元素
    else: // node is a primitive type (String, Number, Boolean, null)
        print "Value:", node