嵌套的json to java对象List<Object>返回期望值，而List<DefinedObject>返回空值

import com.fasterxml.jackson.databind.ObjectMapper;

import java.io.IOException;
import java.util.List;

public class JsonToJavaExample {
    public static void main(String[] args) {
        String json = "{\"data\": [{\"name\": \"John\", \"age\": 25}, {\"name\": \"Jane\", \"age\": 30}]}";

        ObjectMapper objectMapper = new ObjectMapper();

        try {
            // 将JSON转换为List<Object>
            List<Object> objectList = objectMapper.readValue(json, List.class);
            System.out.println("List<Object>: " + objectList);

            // 将JSON转换为List<DefinedObject>
            List<DefinedObject> definedObjectList = objectMapper.readValue(json, objectMapper.getTypeFactory().constructCollectionType(List.class, DefinedObject.class));
            System.out.println("List<DefinedObject>: " + definedObjectList);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    static class DefinedObject {
        private String name;
        private int age;

        // 省略构造函数、getter和setter方法

        @Override
        public String toString() {
            return "DefinedObject{" +
                    "name='" + name + '\'' +
                    ", age=" + age +
                    '}';
        }
    }
}