Springboot 整合 hibernate 和 jpa_spring.jpa.properties.hibernate.dialect

hibernate 和 jpa 的关系这里就不介绍了，你可以这么理解：hibernate用jpa的方式来实现

1.引入依赖  （jpa里面已经有了hiebrnate的依赖包）

<!--整合hibernate要jpa-->
<dependency>
     <groupId>org.springframework.boot</groupId>
     <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
     <groupId>mysql</groupId>
     <artifactId>mysql-connector-java</artifactId>
</dependency>

2.修改 application.properties

datasource的参数跟你整合mybatis一样，不过整合hibernate还得指定jpa的配置

#datasource
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/springboot?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone=UTC
spring.datasource.username=root
spring.datasource.password=123
 
#jpa配置
spring.jpa.database = MYSQL
# Show or not log for each sql query
spring.jpa.show-sql = true
# Hibernate ddl auto (create, create-drop, update)
spring.jpa.hibernate.ddl-auto = update
# Naming strategy
spring.jpa.hibernate.naming-strategy = org.hibernate.cfg.ImprovedNamingStrategy
# stripped before adding them to the entity manager)
spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.MySQL5Dialect

3.创建实体类（这里用注解式开发，没有了.hbm.xml文件）

通过注解将表名和类名，字段名和属性名关联起来，还有指定主键生成策略

package com.liqiye.springbootdemo.entity;
 
import java.io.Serializable;
 
import javax.persistence.Column;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.MappedSuperclass;
import javax.persistence.Entity;
import javax.persistence.Table;
 
/**
 * @author liqiye
 * @description hibernate的实体类
 * @date 2019/5/11
 */
@Entity    // @Entity标识一个实体类，任何Hibernate映射对象都要有这个注解
@Table(name = "Person")
public class Person implements Serializable{
    
    @Id
    // @GeneratedValue(strategy = GenerationType.AUTO)  // 这个和默认一样是以Oracle的方式来实现自增主键，会自动生成hibernate_sequence表
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    protected Long id;
    @Column(name = "name")
    protected String name;
 
    public Long getId() {
        return id;
    }
 
    public void setId(Long id) {
        this.id = id;
    }
 
    public String getName() {
        return name;
    }
 
    public void setName(String name) {
        this.name = name;
    }
 
    @Override
    public String toString() {
        return "Person{" +
                "id=" + id +
                ", name='" + name + '\'' +
                '}';
    }
}

4.定义数据库操作接口

类似mybatis的mapper接口一样，包含操作数据库的方法，注入到service层使用，这里用的jpa，继承 JpaRepository 类

 JpaRepository 的子类已经实现了简单的增删改查的方法，我们也可以自定义HQL的方法

package com.liqiye.springbootdemo.mapper;
 
import com.liqiye.springbootdemo.entity.Person;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.query.Param;
 
// hibernate的接口，springboot整合hibernate用的是jpa，接口要集成JpaRepository
// 里面已经集成了几个方法，额外的查询需要我们手动添加方法HQL
 
public interface PersonRepository extends JpaRepository<Person,Integer> {
    public Person findById(Long id);  // 这个在集成的类的子类里面有明确的sql实现，不用再写SQL或者HQL，也可以不写，直接在service里用子类的
 
    public Person save(Person user);  // 同上
 
    @Query(value = "SELECT p FROM Person p WHERE name=:name")   // 这是HQL  :xx 指传入参数，跟下面注解@Param对应
    // @Query(value = "SELECT * FROM Person WHERE name=?", nativeQuery = true)   // 这是SQL   nativeQuery为true代表使用SQL语言
    public Person findByName(@Param("name") String name);
 
}

5.service 

package com.liqiye.springbootdemo.service;
 
import com.liqiye.springbootdemo.entity.Person;
import com.liqiye.springbootdemo.mapper.PersonRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
 
/**
 * @author liqiye
 * @description
 * @date 2019/5/11
 */
@Service
public class PersonService {
 
    @Autowired
    private PersonRepository personRepository;
 
    public Person findById(Long id){
        return personRepository.findById(id);
    }
 
    public Person findByName(String name){
        return personRepository.findByName(name);
    }
 
    public void save(Person person){
        personRepository.save(person);
    }
 
}

5.controller

package com.liqiye.springbootdemo.controller;
 
import com.liqiye.springbootdemo.entity.Person;
import com.liqiye.springbootdemo.service.PersonService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
 
/**
 * @author liqiye
 * @description
 * @date 2019/5/11
 */
@Controller
public class PersonController {
 
    @Autowired
    private PersonService personService;
 
    @RequestMapping("/findById")
    @ResponseBody
    public String findById(String id){
        return personService.findById(Long.parseLong(id)).toString();
    }
 
    @RequestMapping("/findByName")
    @ResponseBody
    public String findByName(String name){
        return personService.findByName(name).toString();
    }
 
    @RequestMapping("/save")
    @ResponseBody
    public String save(){
        Person person = new Person();
        person.setName("张三");
        personService.save(person);
        return "插入成功";
    }
 
}

6.测试

运行项目，发现数据库自动创建了person 表

发起接口请求 http://localhost:8080/save 成功插入数据

发起接口请求 http://localhost:8080/findById?id=1 成功返回一条person数据

发起接口请求 http://localhost:8080/findByName?name=张三 成功返回一条person数据

总结：整体下来，跟整合mybatis的用法大同小异，只不过其中的具体实现有点差别。