Caused by org.hibernate.AnnotationException No identifier specified for entity：com.beans.UserInfo

Causedby:org.hibernate.AnnotationException: No identifier specified for entity:

这是在SpringBoot 整合SpringDataJPA写测试类遇到的错误：
意思是说：根据Hinbernate的规范，一定要为实体类添加唯一的标识符，即主键id。在私有变量或set方法之上添加注解即可。

例：

@Id 

@GeneratedValue

private int id;

但是，我是有这些注解的。
通过一系列的排查，终于找到了问题所在，问题在于注解导入的包有错，之前自动导的是spring的包，
import org.springframework.data.annotation.Id;

正确的注解导包是：

import javax.persistence.Entity;

import javax.persistence.GeneratedValue;

import javax.persistence.GenerationType;

import javax.persistence.Id;

实体类代码：

package com.beans;



import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;


@Entity
public class UserInfo {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Integer id;

    private String userName;
    private String password;
    private String note;


    @Override
    public String toString() {
        return "UserInfo{" +
                "id=" + id +
                ", userName='" + userName + '\'' +
                ", password='" + password + '\'' +
                ", note='" + note + '\'' +
                '}';
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getNote() {
        return note;
    }

    public void setNote(String note) {
        this.note = note;
    }
}

UserDao接口：

package com.dao;

import com.beans.UserInfo;

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


/**
 * 要继承于Jpa提供的某个接口，并提供泛型，前面的是指要操作哪个类型的对象，后面是指主键类型
 */
public interface UserDao extends JpaRepository<UserInfo,Integer> {

    //这里不用写任何东西
}

UserDaoTest测试类：

package com.test;

import com.SpringdataJpaApplication;
import com.beans.UserInfo;
import com.dao.UserDao;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import javax.annotation.Resource;

import static org.junit.Assert.*;
@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = SpringdataJpaApplication.class)//主启动类.class
public class UserDaoTest {

    @Resource	//Spring注入
    UserDao userDao;
    @Test
    public void testSave() {
        UserInfo user=new UserInfo();
        user.setId(2);
        user.setUserName("root");
        user.setPassword("pwdaaa123");
        user.setNote("这是一个jpa用户");

        userDao.save(user);
        System.out.println("用户添加成功");

    }

    
}

application.properties配置文件：

spring.datasource.driverClassName=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/springboot?characterEncoding=utf8&useSSL=false&rewriteBatchedStatements=true&serverTimezone=UTC
spring.datasource.username=root
spring.datasource.password=Root

spring.datasource.type=com.alibaba.druid.pool.DruidDataSource

spring.jpa.hibernate.ddl-auto=update
spring.jpa.show-sql=true
spring.jpa.hibernate.naming.physical-strategy=org.hibernate.boot.model.naming.PhysicalNamingStrategyStandardImpl