如何为Jackson编写自定义JSON反序列化程序？

import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.JsonDeserializer;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;

import java.io.IOException;

public class CustomDeserializer extends JsonDeserializer<CustomObject> {

    @Override
    public CustomObject deserialize(JsonParser jsonParser, DeserializationContext deserializationContext) throws IOException {
        ObjectMapper objectMapper = new ObjectMapper();
        JsonNode rootNode = jsonParser.getCodec().readTree(jsonParser);

        // 解析和转换JSON数据
        String name = rootNode.get("name").asText();
        int age = rootNode.get("age").asInt();

        // 创建自定义对象
        CustomObject customObject = new CustomObject(name, age);

        return customObject;
    }
}

@JsonDeserialize(using = CustomDeserializer.class)
public class CustomObject {
    // 类定义
}