如何使用Jackson框架获取计数所有json节点

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

ObjectMapper objectMapper = new ObjectMapper();

String json = "{\"key1\":\"value1\",\"key2\":\"value2\",\"key3\":\"value3\"}";
JsonNode rootNode = objectMapper.readTree(json);

int nodeCount = rootNode.size();

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

public class JacksonExample {
    public static void main(String[] args) {
        try {
            String json = "{\"key1\":\"value1\",\"key2\":\"value2\",\"key3\":\"value3\"}";

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

            int nodeCount = rootNode.size();
            System.out.println("JSON节点计数：" + nodeCount);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}