jackson使用$ symbol读取节点字段

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

public class JacksonExample {
    public static void main(String[] args) {
        String json = "{\"name\":\"John\", \"age\":30, \"city\":\"New York\"}";

        try {
            ObjectMapper objectMapper = new ObjectMapper();
            JsonNode rootNode = objectMapper.readTree(json);

            // 使用$符号读取节点字段
            String name = rootNode.at("/name").asText();
            int age = rootNode.at("/age").asInt();
            String city = rootNode.at("/city").asText();

            System.out.println("Name: " + name);
            System.out.println("Age: " + age);
            System.out.println("City: " + city);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}