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SpringBoot整合JPA
作者：mmseoamin日期：2023-12-18

SpringBoot整合JPA

1、Spring Data JPA概述

SpringData：Spring 的一个子项目。用于简化数据库访问，支持NoSQL 和 关系数据存储。其主要目标是使数据

库的访问变得方便快捷。

JPA：JPA(Java Persistence API，Java持久化API)，定义了对象关系映射(Object Relation Mapping,ORM)以及实

体对象持久化的标准接口。Hibernate实现了JPA的一个ORM框架。

JPA Spring Data：致力于减少数据访问层 (DAO) 的开发量，开发者唯一要做的，就只是声明持久层的接口，

其他都交给 Spring Data JPA 来完成。Spring Data JPA 是Spring基于ORM框架、JPA规范的基础上封装的一套JPA

应用框架。

2、SpringBoot整合JPA

2.1 建库建表

DROP TABLE IF EXISTS  student ;
CREATE TABLE  student  (
   id  int(11) NOT NULL AUTO_INCREMENT,
   name  varchar(100) DEFAULT NULL,
   sex  varchar(100) DEFAULT NULL,
   age  int(11) DEFAULT NULL,
  PRIMARY KEY ( id )
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;

SpringBoot整合JPA,在这里插入图片描述,第1张

2.2 新建项目

目录结构如下：

SpringBoot整合JPA,在这里插入图片描述,第2张

2.3 添加相关依赖



	4.0.0
	
		org.springframework.boot
		spring-boot-starter-parent
		2.5.4
		
	
	com.jpa.mysql
	spring-data-jpa-mysql
	0.0.1-SNAPSHOT
	spring-data-jpa-mysql
	spring-data-jpa-mysql
	
		1.8
	
	
		
			org.springframework.boot
			spring-boot-starter-web
		
		
			org.springframework.boot
			spring-boot-starter
		
		
			org.springframework.boot
			spring-boot-starter-test
			test
		
		
		
			org.springframework.boot
			spring-boot-starter-data-jpa
		
		
		
			org.projectlombok
			lombok
			true
		
		
			mysql
			mysql-connector-java
		
	
	
		
			
				org.springframework.boot
				spring-boot-maven-plugin

2.4 修改application.properties配置文件

server.port=9000
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://127.0.0.1:3306/test
spring.datasource.username=root
spring.datasource.password=root
spring.jpa.show-sql=true
spring.jpa.database-platform=org.hibernate.dialect.MySQL5Dialect

2.5 编写entity

package com.jpa.mysql.entity;
import lombok.Data;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
import java.io.Serializable;
@Data
@Entity
@Table(name = "student")
public class Student implements Serializable {
    @Id
    @Column(name="id")
    private int id;
    @Column(name="name")
    private String name;
    @Column(name="sex")
    private String sex;
    @Column(name="age")
    private int age;
}

2.6 编写dao

package com.jpa.gbase.dao;
import com.jpa.gbase.entity.Student;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;
import java.util.List;
@Repository
public interface StudentDao extends JpaRepository {
    List findByName(String name);
}

2.6 编写service接口

package com.jpa.gbase.service;
import com.jpa.gbase.entity.Student;
import org.springframework.stereotype.Component;
import java.util.List;
@Component
public interface IStudentService {
    Student findById(Integer id);
    List findAll();
    List findByName(String name);
    Student save(String name) throws Exception;
    void delete(Integer id) throws Exception;
}

2.7 编写service实现类

package com.jpa.gbase.service.impl;
import com.jpa.gbase.dao.StudentDao;
import com.jpa.gbase.entity.Student;
import com.jpa.gbase.service.IStudentService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.transaction.annotation.Transactional;
import java.util.List;
@Component
public class StudentServiceImpl implements IStudentService {
    @Autowired
    private StudentDao studentDao;
    @Override
    public Student findById(Integer id) {
        return studentDao.findById(id).get();
    }
    @Override
    public List findAll() {
        return studentDao.findAll();
    }
    @Override
    public List findByName(String name) {
        return studentDao.findByName(name);
    }
    @Override
    @Transactional
    public Student save(String name) throws Exception {
        Student student = new Student();
        student.setName(name);
        student.setSex("M");
        student.setAge(18);
        return studentDao.save(student);
    }
    @Override
    @Transactional
    public void delete(Integer id) throws Exception {
        studentDao.deleteById(id);
    }
}

2.8 编写controller

package com.jpa.gbase.controller;
import com.jpa.gbase.entity.Student;
import com.jpa.gbase.service.IStudentService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
import java.util.List;
@RestController
@RequestMapping(value = "/student")
public class StudentController {
    @Autowired
    private IStudentService studentService;
    @GetMapping(value = "/findById/{id}")
    public Student findById(@PathVariable("id") Integer id) {
        return studentService.findById(id);
    }
    @GetMapping(value = "/findAll")
    public List findAll() {
        return studentService.findAll();
    }
    @GetMapping(value = "/findByName/{name}")
    public List findByName(@PathVariable("name") String name) {
        return studentService.findByName(name);
    }
    @GetMapping(value = "/save/{name}")
    public Student save(@PathVariable("name") String name) {
        Student student = new Student();
        try {
            student = studentService.save(name);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return student;
    }
    @GetMapping(value = "/delete/{id}")
    public boolean delete(@PathVariable("id") Integer id) {
        boolean flg = false;
        try {
            studentService.delete(id);
            flg = true;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return flg;
    }
}

2.9 编写启动类

package com.jpa.mysql;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class SpringDataJpaMysqlApplication {
	public static void main(String[] args) {
		SpringApplication.run(SpringDataJpaMysqlApplication.class, args);
	}
}

3.测试

3.1 添加数据

http://localhost:9000/student/save/tom

SpringBoot整合JPA,在这里插入图片描述,第3张

3.2 根据id查询数据

http://localhost:9000/student/findById/1

SpringBoot整合JPA,在这里插入图片描述,第4张

3.3 根据名字查询数据

http://localhost:9000/student/findByName/tom

SpringBoot整合JPA,在这里插入图片描述,第5张

3.4 根据id删除数据

http://localhost:9000/student/delete/1

SpringBoot整合JPA,在这里插入图片描述,第6张

3.5 查询全部数据

http://localhost:9000/student/save/tom1
http://localhost:9000/student/save/tom2
http://localhost:9000/student/save/tom3
http://localhost:9000/student/save/tom4
http://localhost:9000/student/save/tom5
http://localhost:9000/student/findAll

SpringBoot整合JPA,在这里插入图片描述,第7张

4、简单查询

基本查询也分为两种，一种是 Spring Data 默认已经实现，一种是根据查询的方法来自动解析成 SQL。

4.1 预先生成方法

Spring Boot Jpa 默认预先生成了一些基本的CURD的方法，例如：增、删、改等等

1、继承 JpaRepository

@Repository
public interface StudentDao extends JpaRepository {
}

2、使用默认方法

@Autowired
private StudentDao studentDao;
studentDao.findAll();
studentDao.findOne(1l);
studentDao.save(user);
studentDao.delete(user);
studentDao.count();
studentDao.exists(1l);

4.2 自定义简单查询

自定义的简单查询就是根据方法名来自动生成 SQL。

主要的语法是 findByXX,readAByXX,queryByXX,countByXX, getByXX ，XX 代表属性名称。

Student findByName(String name);

也使用一些加一些关键字And 、 Or：

User findByNameOrSex(String username, int sex);

修改、删除、统计也是类似语法：

Long deleteById(Long id);
Long countByName(String mame);

基本上 SQL 体系中的关键词都可以使用，例如：LIKE、 IgnoreCase、 OrderBy。

List findByNameLike(String name);
Student findByNameIgnoreCase(String name);
List findByNameOrderByAgeDesc(String name);

具体的关键字，使用方法和生产成SQL如下表所示：

KeywordSampleJPQL snippet
AndfindByLastnameAndFirstname… where x.lastname = ?1 and x.firstname = ?2
OrfindByLastnameOrFirstname… where x.lastname = ?1 or x.firstname = ?2
Is,EqualsfindByFirstnameIs,findByFirstnameEquals… where x.firstname = ?1
BetweenfindByStartDateBetween… where x.startDate between ?1 and ?2
LessThanfindByAgeLessThan… where x.age < ?1
LessThanEqualfindByAgeLessThanEqual… where x.age <= ?1
GreaterThanfindByAgeGreaterThan… where x.age > ?1
GreaterThanEqualfindByAgeGreaterThanEqual… where x.age >= ?1
AfterfindByStartDateAfter… where x.startDate > ?1
BeforefindByStartDateBefore… where x.startDate < ?1
IsNullfindByAgeIsNull… where x.age is null
IsNotNull,NotNullfindByAge(Is)NotNull… where x.age not null
LikefindByFirstnameLike… where x.firstname like ?1
NotLikefindByFirstnameNotLike… where x.firstname not like ?1
StartingWithfindByFirstnameStartingWith… where x.firstname like ?1 (parameter bound with appended %)
EndingWithfindByFirstnameEndingWith… where x.firstname like ?1 (parameter bound with prepended %)
ContainingfindByFirstnameContaining… where x.firstname like ?1 (parameter bound wrapped in %)
OrderByfindByAgeOrderByLastnameDesc… where x.age = ?1 order by x.lastname desc
NotfindByLastnameNot… where x.lastname <> ?1
InfindByAgeIn(Collection ages)… where x.age in ?1
NotInfindByAgeNotIn(Collection age)… where x.age not in ?1
TRUEfindByActiveTrue()… where x.active = true
FALSEfindByActiveFalse()… where x.active = false
IgnoreCasefindByFirstnameIgnoreCase… where UPPER(x.firstame) = UPPER(?1)

5、复杂查询

在实际的开发中我们需要用到分页、删选、连表等查询的时候就需要特殊的方法或者自定义 SQL。

5.1 分页查询

分页查询在实际使用中非常普遍了，Spring Boot Jpa 已经帮我们实现了分页的功能，在查询的方法中，需要传入

参数Pageable ，当查询中有多个参数的时候Pageable建议做为最后一个参数传入。

Page findALL(Pageable pageable);
Page findByName(String name,Pageable pageable);

Pageable 是 Spring 封装的分页实现类，使用的时候需要传入页数、每页条数和排序规则。

@Test
public void testPageQuery() throws Exception {
	int page=1,size=10;
	Sort sort = new Sort(Direction.DESC, "id");
    Pageable pageable = new PageRequest(page, size, sort);
    studentDao.findALL(pageable);
    studentDao.findByName("tom", pageable);
}

5.2 限制查询

有时候我们只需要查询前N个元素，或者只取前一个实体。

Student findFirstByOrderByNameAsc();
Student findTopByOrderByAgeDesc();
Page queryFirst10ByName(String name, Pageable pageable);
List findFirst10ByName(String name, Sort sort);
List findTop10ByName(String name, Pageable pageable);

5.3 自定义SQL查询

其实 Spring Data 觉大部分的 SQL 都可以根据方法名定义的方式来实现，但是由于某些原因我们想使用自定义的

SQL 来查询，Spring Data 也是完美支持的；在 SQL 的查询方法上面使用@Query注解，如涉及到删除和修改再需

要加上@Modifying，也可以根据需要添加 @Transactional对事物的支持，查询超时的设置等。

@Modifying
@Query("update student stu set stu.name = ?1 where stu.id = ?2")
int modifyNameById(String name, Long id);
	
@Transactional
@Modifying
@Query("delete from student where id = ?1")
void deleteById(Long id);
@Transactional(timeout = 10)
@Query("select stu from student stu where stu.id = ?1")
User findById(Long id);

5.4 多表查询

多表查询 Spring Boot Jpa 中有两种实现方式，第一种是利用 Hibernate 的级联查询来实现，第二种是创建一个结

果集的接口来接收连表查询后的结果，这里主要第二种方式。

首先需要定义一个结果集的接口类：

public interface HotelSummary {
	City getCity();
	String getName();
	Double getAverageRating();
	default Integer getAverageRatingRounded() {
		return getAverageRating() == null ? null : (int) Math.round(getAverageRating());
	}
}

查询的方法返回类型设置为新创建的接口：

@Query("select h.city as city, h.name as name, avg(r.rating) as averageRating "
		- "from Hotel h left outer join h.reviews r where h.city = ?1 group by h")
Page findByCity(City city, Pageable pageable);
@Query("select h.name as name, avg(r.rating) as averageRating "
		- "from Hotel h left outer join h.reviews r  group by h")
Page findByCity(Pageable pageable);

使用：

Page hotels = this.hotelRepository.findByCity(new PageRequest(0, 10, Direction.ASC, "name"));
for(HotelSummary summay:hotels){
		System.out.println("Name" +summay.getName());
	}

在运行中 Spring 会给接口（HotelSummary）自动生产一个代理类来接收返回的结果，代码汇总使用 getXX

的形式来获取。

6、使用枚举

使用枚举的时候，我们希望数据库中存储的是枚举对应的 String 类型，而不是枚举的索引值，需要在属性上面添

加@Enumerated(EnumType.STRING) 注解

@Enumerated(EnumType.STRING) 
@Column(nullable = true)
private UserType type;

7、不需要和数据库映射的属性

正常情况下我们在实体类上加入注解@Entity，就会让实体类和表相关连如果其中某个属性我们不需要和数据库

来关联只是在展示的时候做计算，只需要加上@Transient属性既可。

@Transient
private String userName;

8、多数据源的支持

8.1 同源数据库的多源支持

日常项目中因为使用的分布式开发模式，不同的服务有不同的数据源，常常需要在一个项目中使用多个数据源，因

此需要配置 Spring Boot Jpa 对多数据源的使用，一般分一下为三步：

  • 1 配置多数据源

  • 2 不同源的实体类放入不同包路径

  • 3 声明不同的包路径下使用不同的数据源、事务支持

    8.2 异构数据库多源支持

    比如我们的项目中，即需要对 mysql 的支持，也需要对 Mongodb 的查询等。

    实体类声明@Entity 关系型数据库支持类型，声明@Document 为 Mongodb 支持类型，不同的数据源使用不同的

    实体就可以了。

    interface PersonRepository extends Repository {
 …
}
@Entity
public class Person {
  …
}
interface UserRepository extends Repository {
 …
}
@Document
public class User {
  …
}

    但是，如果 User 用户既使用 Mysql 也使用 Mongodb 呢，也可以做混合使用。

    interface JpaPersonRepository extends Repository {
 …
}
interface MongoDBPersonRepository extends Repository {
 …
}
@Entity
@Document
public class Person {
  …
}

    也可以通过对不同的包路径进行声明，比如 A 包路径下使用 mysql，B 包路径下使用 MongoDB。

    @EnableJpaRepositories(basePackages = "com.neo.repositories.jpa")
@EnableMongoRepositories(basePackages = "com.neo.repositories.mongo")
interface Configuration { }

    9、多数据源使用案例

    9.1 导入pom依赖

    

    4.0.0
    
        org.springframework.boot
        spring-boot-starter-parent
        2.5.4
        
    
    com.example
    spring-boot-multi-jpa
    0.0.1-SNAPSHOT
    spring-boot-multi-jpa
    spring-boot-multi-Jpa
    
        UTF-8
        1.8
    
    
        
            org.springframework.boot
            spring-boot-starter-web
        
        
            org.springframework.boot
            spring-boot-starter
        
        
            org.springframework.boot
            spring-boot-starter-test
            test
        
        
            org.springframework.boot
            spring-boot-starter-data-jpa
        
        
            mysql
            mysql-connector-java
        
        
        
            org.projectlombok
            lombok
            true
        
        
            junit
            junit
            test
        
    
    
        
            
                org.springframework.boot
                spring-boot-maven-plugin

    9.2 配置文件

    spring.datasource.primary.jdbc-url=jdbc:mysql://localhost:3306/test1?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8&useSSL=true
spring.datasource.primary.username=root
spring.datasource.primary.password=root
spring.datasource.primary.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.secondary.jdbc-url=jdbc:mysql://localhost:3306/test2?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8&useSSL=true
spring.datasource.secondary.username=root
spring.datasource.secondary.password=root
spring.datasource.secondary.driver-class-name=com.mysql.cj.jdbc.Driver
spring.jpa.show-sql=true
spring.jpa.properties.hibernate.hbm2ddl.auto=create
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL5InnoDBDialect
spring.jpa.properties.hibernate.format_sql=true

    9.3 实体类

    package com.example.springbootmultijpa.model;
import lombok.AllArgsConstructor;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;
import javax.persistence.*;
import java.io.Serializable;
@Getter
@Setter
@Entity
@NoArgsConstructor
@AllArgsConstructor
public class User implements Serializable {
    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id")
    private long id;
    @Column(nullable = false, unique = true)
    private String userName;
    @Column(nullable = false)
    private String passWord;
    @Column(nullable = false, unique = true)
    private String email;
    @Column(nullable = true, unique = true)
    private String nickName;
    @Column(nullable = false)
    private String regTime;
    public User(String userName, String passWord, String email, String nickName, String regTime) {
        this.userName = userName;
        this.passWord = passWord;
        this.email = email;
        this.nickName = nickName;
        this.regTime = regTime;
    }
}

    9.4 config

    package com.example.springbootmultijpa.config;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.orm.jpa.HibernateProperties;
import org.springframework.boot.autoconfigure.orm.jpa.HibernateSettings;
import org.springframework.boot.autoconfigure.orm.jpa.JpaProperties;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import javax.sql.DataSource;
import java.util.Map;
@Configuration
public class DataSourceConfig {
    @Autowired
    private JpaProperties jpaProperties;
    @Autowired
    private HibernateProperties hibernateProperties;
    @Bean(name = "primaryDataSource")
    @Primary
    @ConfigurationProperties("spring.datasource.primary")
    public DataSource firstDataSource() {
        return DataSourceBuilder.create().build();
    }
    @Bean(name = "secondaryDataSource")
    @ConfigurationProperties("spring.datasource.secondary")
    public DataSource secondDataSource() {
        return DataSourceBuilder.create().build();
    }
    @Bean(name = "vendorProperties")
    public Map getVendorProperties() {
        return hibernateProperties.determineHibernateProperties(jpaProperties.getProperties(),
                new HibernateSettings());
    }
}

    package com.example.springbootmultijpa.config;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.orm.jpa.EntityManagerFactoryBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
import org.springframework.orm.jpa.JpaTransactionManager;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
import org.springframework.transaction.PlatformTransactionManager;
import org.springframework.transaction.annotation.EnableTransactionManagement;
import javax.persistence.EntityManager;
import javax.sql.DataSource;
import java.util.Map;
@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(
        entityManagerFactoryRef = "entityManagerFactoryPrimary",
        transactionManagerRef = "transactionManagerPrimary",
        basePackages = {"com.example.springbootmultijpa.repository.test1"})//设置dao（repo）所在位置
public class PrimaryConfig {
    @Autowired
    @Qualifier("primaryDataSource")
    private DataSource primaryDataSource;
    @Autowired
    @Qualifier("vendorProperties")
    private Map vendorProperties;
    @Bean(name = "entityManagerFactoryPrimary")
    @Primary
    public LocalContainerEntityManagerFactoryBean entityManagerFactoryPrimary(EntityManagerFactoryBuilder builder) {
        return builder
                .dataSource(primaryDataSource)
                .properties(vendorProperties)
                .packages("com.example.springbootmultijpa.model") //设置实体类所在位置
                .persistenceUnit("primaryPersistenceUnit")
                .build();
    }
    @Bean(name = "entityManagerPrimary")
    @Primary
    public EntityManager entityManager(EntityManagerFactoryBuilder builder) {
        return entityManagerFactoryPrimary(builder).getObject().createEntityManager();
    }
    @Bean(name = "transactionManagerPrimary")
    @Primary
    PlatformTransactionManager transactionManagerPrimary(EntityManagerFactoryBuilder builder) {
        return new JpaTransactionManager(entityManagerFactoryPrimary(builder).getObject());
    }
}

    package com.example.springbootmultijpa.config;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.orm.jpa.EntityManagerFactoryBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
import org.springframework.orm.jpa.JpaTransactionManager;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
import org.springframework.transaction.PlatformTransactionManager;
import org.springframework.transaction.annotation.EnableTransactionManagement;
import javax.persistence.EntityManager;
import javax.sql.DataSource;
import java.util.Map;
@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(
        entityManagerFactoryRef = "entityManagerFactorySecondary",
        transactionManagerRef = "transactionManagerSecondary",
        basePackages = {"com.example.springbootmultijpa.repository.test2"})
public class SecondaryConfig {
    @Autowired
    @Qualifier("secondaryDataSource")
    private DataSource secondaryDataSource;
    @Autowired
    @Qualifier("vendorProperties")
    private Map vendorProperties;
    @Bean(name = "entityManagerFactorySecondary")
    public LocalContainerEntityManagerFactoryBean entityManagerFactorySecondary(EntityManagerFactoryBuilder builder) {
        return builder
                .dataSource(secondaryDataSource)
                .properties(vendorProperties)
                .packages("com.example.springbootmultijpa.model")
                .persistenceUnit("secondaryPersistenceUnit")
                .build();
    }
    @Bean(name = "entityManagerSecondary")
    public EntityManager entityManager(EntityManagerFactoryBuilder builder) {
        return entityManagerFactorySecondary(builder).getObject().createEntityManager();
    }
    @Bean(name = "transactionManagerSecondary")
    PlatformTransactionManager transactionManagerSecondary(EntityManagerFactoryBuilder builder) {
        return new JpaTransactionManager(entityManagerFactorySecondary(builder).getObject());
    }
}

    9.5 Repository

    package com.example.springbootmultijpa.repository.test1;
import com.example.springbootmultijpa.model.User;
import org.springframework.data.jpa.repository.JpaRepository;
public interface UserTest1Repository extends JpaRepository {
    User findById(long id);
    User findByUserName(String userName);
    User findByUserNameOrEmail(String username, String email);
}

    package com.example.springbootmultijpa.repository.test2;
import com.example.springbootmultijpa.model.User;
import org.springframework.data.jpa.repository.JpaRepository;
public interface UserTest2Repository extends JpaRepository {
    User findById(long id);
    User findByUserName(String userName);
    User findByUserNameOrEmail(String username, String email);
}

    9.6 启动类

    package com.example.springbootmultijpa;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class SpringBootMultiJpaApplication {
    public static void main(String[] args) {
        SpringApplication.run(SpringBootMultiJpaApplication.class, args);
    }
}

    9.7 测试

    package com.example.springbootmultijpa.repository;
import com.example.springbootmultijpa.model.User;
import com.example.springbootmultijpa.repository.test1.UserTest1Repository;
import com.example.springbootmultijpa.repository.test2.UserTest2Repository;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;
import javax.annotation.Resource;
import java.text.DateFormat;
import java.util.Date;
@RunWith(SpringRunner.class)
@SpringBootTest
public class UserRepositoryTests {
    @Resource
    private UserTest1Repository userTest1Repository;
    @Resource
    private UserTest2Repository userTest2Repository;
    @Test
    public void testSave() throws Exception {
        Date date = new Date();
        DateFormat dateFormat = DateFormat.getDateTimeInstance(DateFormat.LONG, DateFormat.LONG);
        String formattedDate = dateFormat.format(date);
        userTest1Repository.save(new User("aa", "aa123456", "aa@126.com", "aa", formattedDate));
        userTest1Repository.save(new User("bb", "bb123456", "bb@126.com", "bb", formattedDate));
        userTest2Repository.save(new User("cc", "cc123456", "cc@126.com", "cc", formattedDate));
    }
    @Test
    public void testDelete() throws Exception {
        userTest1Repository.deleteAll();
        userTest2Repository.deleteAll();
    }
    @Test
    public void testBaseQuery() {
        Date date = new Date();
        DateFormat dateFormat = DateFormat.getDateTimeInstance(DateFormat.LONG, DateFormat.LONG);
        String formattedDate = dateFormat.format(date);
        User user = new User("ff", "ff123456", "ff@126.com", "ff", formattedDate);
        userTest1Repository.findAll();
        userTest2Repository.findById(3l);
        userTest2Repository.save(user);
        user.setId(2l);
        userTest1Repository.delete(user);
        userTest1Repository.count();
        userTest2Repository.findById(3l);
    }
}

    运行testSave()得到的结果：

    SpringBoot整合JPA,在这里插入图片描述,第8张

    运行testBaseQuery()得到的结果：

    SpringBoot整合JPA,在这里插入图片描述,第9张

    运行testDelete()得到的结果：

    SpringBoot整合JPA,在这里插入图片描述,第10张

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