如何使用java从子jsonnode获取值

<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.12.5</version>
</dependency>

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

ObjectMapper objectMapper = new ObjectMapper();

String jsonString = "{\"name\":\"John\", \"age\":30, \"city\":\"New York\"}";
JsonNode jsonNode = objectMapper.readTree(jsonString);

String name = jsonNode.get("name").asText();
int age = jsonNode.get("age").asInt();
String city = jsonNode.get("city").asText();