我是使用JPA的新手，我正在阅读在线教程，它们都是从JPARespository扩展而来的，如下所示
从本页
https://www.callicoder.com/spring-boot-jpa-hibernate-postgresql-restful-crud-api-example/

package com.example.postgresdemo.repository;

import com.example.postgresdemo.model.Answer;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;
import java.util.List;

@Repository
public interface AnswerRepository extends JpaRepository<Answer, Long> {
    List<Answer> findByQuestionId(Long questionId);
}

但是在我的项目中，Eclipse抱怨如下

The type JpaRepository<Property,Long> cannot be the superclass of PropertyRepository; a superclass must be a class

下面是我的课

package realestate.repository;

import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;

import realestate.model.Property;

import java.util.List;

@Repository
public class PropertyRepository extends JpaRepository<Property, Long> {

}