SpringBoot整合JPA

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;

2.2 新建项目

目录结构如下：

2.3 添加相关依赖

<?xml version="1.0" encoding="UTF-8"?><projectxmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>2.5.4</version><relativePath/></parent><groupId>com.jpa.mysql</groupId><artifactId>spring-data-jpa-mysql</artifactId><version>0.0.1-SNAPSHOT</version><name>spring-data-jpa-mysql</name><description>spring-data-jpa-mysql</description><properties><java.version>1.8</java.version></properties><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency><!-- jpa 依赖--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-jpa</artifactId></dependency><!-- lombok 依赖--><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><optional>true</optional></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId></dependency></dependencies><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin></plugins></build></project>

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

packagecom.jpa.mysql.entity;importlombok.Data;importjavax.persistence.Column;importjavax.persistence.Entity;importjavax.persistence.Id;importjavax.persistence.Table;importjava.io.Serializable;@Data@Entity@Table(name ="student")publicclassStudentimplementsSerializable{@Id@Column(name="id")privateint id;@Column(name="name")privateString name;@Column(name="sex")privateString sex;@Column(name="age")privateint age;}

2.6 编写dao

packagecom.jpa.gbase.dao;importcom.jpa.gbase.entity.Student;importorg.springframework.data.jpa.repository.JpaRepository;importorg.springframework.stereotype.Repository;importjava.util.List;@RepositorypublicinterfaceStudentDaoextendsJpaRepository<Student,Integer>{List<Student>findByName(String name);}

2.6 编写service接口

packagecom.jpa.gbase.service;importcom.jpa.gbase.entity.Student;importorg.springframework.stereotype.Component;importjava.util.List;@ComponentpublicinterfaceIStudentService{StudentfindById(Integer id);List<Student>findAll();List<Student>findByName(String name);Studentsave(String name)throwsException;voiddelete(Integer id)throwsException;}

2.7 编写service实现类

packagecom.jpa.gbase.service.impl;importcom.jpa.gbase.dao.StudentDao;importcom.jpa.gbase.entity.Student;importcom.jpa.gbase.service.IStudentService;importorg.springframework.beans.factory.annotation.Autowired;importorg.springframework.stereotype.Component;importorg.springframework.transaction.annotation.Transactional;importjava.util.List;@ComponentpublicclassStudentServiceImplimplementsIStudentService{@AutowiredprivateStudentDao studentDao;@OverridepublicStudentfindById(Integer id){return studentDao.findById(id).get();}@OverridepublicList<Student>findAll(){return studentDao.findAll();}@OverridepublicList<Student>findByName(String name){return studentDao.findByName(name);}@Override@TransactionalpublicStudentsave(String name)throwsException{Student student =newStudent();
        student.setName(name);
        student.setSex("M");
        student.setAge(18);return studentDao.save(student);}@Override@Transactionalpublicvoiddelete(Integer id)throwsException{
        studentDao.deleteById(id);}}

2.8 编写controller

packagecom.jpa.gbase.controller;importcom.jpa.gbase.entity.Student;importcom.jpa.gbase.service.IStudentService;importorg.springframework.beans.factory.annotation.Autowired;importorg.springframework.web.bind.annotation.GetMapping;importorg.springframework.web.bind.annotation.RequestMapping;importorg.springframework.web.bind.annotation.PathVariable;importorg.springframework.web.bind.annotation.RestController;importjava.util.List;@RestController@RequestMapping(value ="/student")publicclassStudentController{@AutowiredprivateIStudentService studentService;@GetMapping(value ="/findById/{id}")publicStudentfindById(@PathVariable("id")Integer id){return studentService.findById(id);}@GetMapping(value ="/findAll")publicList<Student>findAll(){return studentService.findAll();}@GetMapping(value ="/findByName/{name}")publicList<Student>findByName(@PathVariable("name")String name){return studentService.findByName(name);}@GetMapping(value ="/save/{name}")publicStudentsave(@PathVariable("name")String name){Student student =newStudent();try{
            student = studentService.save(name);}catch(Exception e){
            e.printStackTrace();}return student;}@GetMapping(value ="/delete/{id}")publicbooleandelete(@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

packagecom.jpa.mysql;importorg.springframework.boot.SpringApplication;importorg.springframework.boot.autoconfigure.SpringBootApplication;@SpringBootApplicationpublicclassSpringDataJpaMysqlApplication{publicstaticvoidmain(String[] args){SpringApplication.run(SpringDataJpaMysqlApplication.class, args);}}

3.测试

3.1 添加数据

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

3.2 根据id查询数据

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

3.3 根据名字查询数据

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

3.4 根据id删除数据

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

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

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

@RepositorypublicinterfaceStudentDaoextendsJpaRepository<Student,Integer>{}

2、使用默认方法

@AutowiredprivateStudentDao 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。

StudentfindByName(String name);

也使用一些加一些关键字

And 

、

Or

：

UserfindByNameOrSex(String username,int sex);

修改、删除、统计也是类似语法：

LongdeleteById(Long id);LongcountByName(String mame);

基本上 SQL 体系中的关键词都可以使用，例如：

LIKE

、

IgnoreCase

、

OrderBy

。

List<Student>findByNameLike(String name);StudentfindByNameIgnoreCase(String name);List<Student>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

And

findByLastnameAndFirstname

… where x.lastname = ?1 and x.firstname = ?2

Or

findByLastnameOrFirstname

… where x.lastname = ?1 or x.firstname = ?2

Is,Equals

findByFirstnameIs,findByFirstnameEquals

… where x.firstname = ?1

Between

findByStartDateBetween

… where x.startDate between ?1 and ?2

LessThan

findByAgeLessThan

… where x.age < ?1

LessThanEqual

findByAgeLessThanEqual

… where x.age <= ?1

GreaterThan

findByAgeGreaterThan

… where x.age > ?1

GreaterThanEqual

findByAgeGreaterThanEqual

… where x.age >= ?1

After

findByStartDateAfter

… where x.startDate > ?1

Before

findByStartDateBefore

… where x.startDate < ?1

IsNull

findByAgeIsNull

… where x.age is null

IsNotNull,NotNull

findByAge(Is)NotNull

… where x.age not null

Like

findByFirstnameLike

… where x.firstname like ?1

NotLike

findByFirstnameNotLike

… where x.firstname not like ?1

StartingWith

findByFirstnameStartingWith

… where x.firstname like ?1 (parameter bound with appended %)

EndingWith

findByFirstnameEndingWith

… where x.firstname like ?1 (parameter bound with prepended %)

Containing

findByFirstnameContaining

… where x.firstname like ?1 (parameter bound wrapped in %)

OrderBy

findByAgeOrderByLastnameDesc

… where x.age = ?1 order by x.lastname desc

Not

findByLastnameNot

… where x.lastname <> ?1

In

findByAgeIn(Collection ages)

… where x.age in ?1

NotIn

findByAgeNotIn(Collection age)

… where x.age not in ?1

TRUE

findByActiveTrue()

… where x.active = true

FALSE

findByActiveFalse()

… where x.active = false

IgnoreCase

findByFirstnameIgnoreCase

… 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<Student>findALL(Pageable pageable);Page<Student>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。

@TestpublicvoidtestPageQuery()throwsException{int page=1,size=10;Sort sort =newSort(Direction.DESC,"id");Pageable pageable =newPageRequest(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。

StudentfindFirstByOrderByNameAsc();StudentfindTopByOrderByAgeDesc();Page<Student>queryFirst10ByName(String name,Pageable pageable);List<Student>findFirst10ByName(String name,Sort sort);List<Student>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")intmodifyNameById(String name,Long id);@Transactional@Modifying@Query("delete from student where id = ?1")voiddeleteById(Long id);@Transactional(timeout =10)@Query("select stu from student stu where stu.id = ?1")UserfindById(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：

publicinterfaceHotelSummary{CitygetCity();StringgetName();DoublegetAverageRating();defaultIntegergetAverageRatingRounded(){returngetAverageRating()==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<HotelSummary>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<HotelSummary>findByCity(Pageable pageable);

使用：

Page<HotelSummary> hotels =this.hotelRepository.findByCity(newPageRequest(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)privateUserType 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。

@TransientprivateString 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。

interfacePersonRepositoryextendsRepository<Person,Long>{
 …
}@EntitypublicclassPerson{
  …
}interfaceUserRepositoryextendsRepository<User,Long>{
 …
}@DocumentpublicclassUser{
  …
}

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

interfaceJpaPersonRepositoryextendsRepository<Person,Long>{
 …
}interfaceMongoDBPersonRepositoryextendsRepository<Person,Long>{
 …
}@Entity@DocumentpublicclassPerson{
  …
}

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")interfaceConfiguration{}

9、多数据源使用案例

9.1 导入pom依赖

<?xml version="1.0" encoding="UTF-8"?><projectxmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>2.5.4</version><relativePath/></parent><groupId>com.example</groupId><artifactId>spring-boot-multi-jpa</artifactId><version>0.0.1-SNAPSHOT</version><name>spring-boot-multi-jpa</name><description>spring-boot-multi-Jpa</description><properties><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding><java.version>1.8</java.version></properties><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-jpa</artifactId></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId></dependency><!-- lombok 依赖--><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><optional>true</optional></dependency><dependency><groupId>junit</groupId><artifactId>junit</artifactId><scope>test</scope></dependency></dependencies><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin></plugins></build></project>

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

packagecom.example.springbootmultijpa.model;importlombok.AllArgsConstructor;importlombok.Getter;importlombok.NoArgsConstructor;importlombok.Setter;importjavax.persistence.*;importjava.io.Serializable;@Getter@Setter@Entity@NoArgsConstructor@AllArgsConstructorpublicclassUserimplementsSerializable{privatestaticfinallong serialVersionUID =1L;@Id@GeneratedValue(strategy =GenerationType.IDENTITY)@Column(name ="id")privatelong id;@Column(nullable =false, unique =true)privateString userName;@Column(nullable =false)privateString passWord;@Column(nullable =false, unique =true)privateString email;@Column(nullable =true, unique =true)privateString nickName;@Column(nullable =false)privateString regTime;publicUser(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

packagecom.example.springbootmultijpa.config;importorg.springframework.beans.factory.annotation.Autowired;importorg.springframework.boot.autoconfigure.orm.jpa.HibernateProperties;importorg.springframework.boot.autoconfigure.orm.jpa.HibernateSettings;importorg.springframework.boot.autoconfigure.orm.jpa.JpaProperties;importorg.springframework.boot.context.properties.ConfigurationProperties;importorg.springframework.boot.jdbc.DataSourceBuilder;importorg.springframework.context.annotation.Bean;importorg.springframework.context.annotation.Configuration;importorg.springframework.context.annotation.Primary;importjavax.sql.DataSource;importjava.util.Map;@ConfigurationpublicclassDataSourceConfig{@AutowiredprivateJpaProperties jpaProperties;@AutowiredprivateHibernateProperties hibernateProperties;@Bean(name ="primaryDataSource")@Primary@ConfigurationProperties("spring.datasource.primary")publicDataSourcefirstDataSource(){returnDataSourceBuilder.create().build();}@Bean(name ="secondaryDataSource")@ConfigurationProperties("spring.datasource.secondary")publicDataSourcesecondDataSource(){returnDataSourceBuilder.create().build();}@Bean(name ="vendorProperties")publicMap<String,Object>getVendorProperties(){return hibernateProperties.determineHibernateProperties(jpaProperties.getProperties(),newHibernateSettings());}}

packagecom.example.springbootmultijpa.config;importorg.springframework.beans.factory.annotation.Autowired;importorg.springframework.beans.factory.annotation.Qualifier;importorg.springframework.boot.orm.jpa.EntityManagerFactoryBuilder;importorg.springframework.context.annotation.Bean;importorg.springframework.context.annotation.Configuration;importorg.springframework.context.annotation.Primary;importorg.springframework.data.jpa.repository.config.EnableJpaRepositories;importorg.springframework.orm.jpa.JpaTransactionManager;importorg.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;importorg.springframework.transaction.PlatformTransactionManager;importorg.springframework.transaction.annotation.EnableTransactionManagement;importjavax.persistence.EntityManager;importjavax.sql.DataSource;importjava.util.Map;@Configuration@EnableTransactionManagement@EnableJpaRepositories(
        entityManagerFactoryRef ="entityManagerFactoryPrimary",
        transactionManagerRef ="transactionManagerPrimary",
        basePackages ={"com.example.springbootmultijpa.repository.test1"})//设置dao（repo）所在位置publicclassPrimaryConfig{@Autowired@Qualifier("primaryDataSource")privateDataSource primaryDataSource;@Autowired@Qualifier("vendorProperties")privateMap<String,Object> vendorProperties;@Bean(name ="entityManagerFactoryPrimary")@PrimarypublicLocalContainerEntityManagerFactoryBeanentityManagerFactoryPrimary(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")@PrimarypublicEntityManagerentityManager(EntityManagerFactoryBuilder builder){returnentityManagerFactoryPrimary(builder).getObject().createEntityManager();}@Bean(name ="transactionManagerPrimary")@PrimaryPlatformTransactionManagertransactionManagerPrimary(EntityManagerFactoryBuilder builder){returnnewJpaTransactionManager(entityManagerFactoryPrimary(builder).getObject());}}

packagecom.example.springbootmultijpa.config;importorg.springframework.beans.factory.annotation.Autowired;importorg.springframework.beans.factory.annotation.Qualifier;importorg.springframework.boot.orm.jpa.EntityManagerFactoryBuilder;importorg.springframework.context.annotation.Bean;importorg.springframework.context.annotation.Configuration;importorg.springframework.data.jpa.repository.config.EnableJpaRepositories;importorg.springframework.orm.jpa.JpaTransactionManager;importorg.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;importorg.springframework.transaction.PlatformTransactionManager;importorg.springframework.transaction.annotation.EnableTransactionManagement;importjavax.persistence.EntityManager;importjavax.sql.DataSource;importjava.util.Map;@Configuration@EnableTransactionManagement@EnableJpaRepositories(
        entityManagerFactoryRef ="entityManagerFactorySecondary",
        transactionManagerRef ="transactionManagerSecondary",
        basePackages ={"com.example.springbootmultijpa.repository.test2"})publicclassSecondaryConfig{@Autowired@Qualifier("secondaryDataSource")privateDataSource secondaryDataSource;@Autowired@Qualifier("vendorProperties")privateMap<String,Object> vendorProperties;@Bean(name ="entityManagerFactorySecondary")publicLocalContainerEntityManagerFactoryBeanentityManagerFactorySecondary(EntityManagerFactoryBuilder builder){return builder
                .dataSource(secondaryDataSource).properties(vendorProperties).packages("com.example.springbootmultijpa.model").persistenceUnit("secondaryPersistenceUnit").build();}@Bean(name ="entityManagerSecondary")publicEntityManagerentityManager(EntityManagerFactoryBuilder builder){returnentityManagerFactorySecondary(builder).getObject().createEntityManager();}@Bean(name ="transactionManagerSecondary")PlatformTransactionManagertransactionManagerSecondary(EntityManagerFactoryBuilder builder){returnnewJpaTransactionManager(entityManagerFactorySecondary(builder).getObject());}}

9.5 Repository

packagecom.example.springbootmultijpa.repository.test1;importcom.example.springbootmultijpa.model.User;importorg.springframework.data.jpa.repository.JpaRepository;publicinterfaceUserTest1RepositoryextendsJpaRepository<User,Long>{UserfindById(long id);UserfindByUserName(String userName);UserfindByUserNameOrEmail(String username,String email);}

packagecom.example.springbootmultijpa.repository.test2;importcom.example.springbootmultijpa.model.User;importorg.springframework.data.jpa.repository.JpaRepository;publicinterfaceUserTest2RepositoryextendsJpaRepository<User,Long>{UserfindById(long id);UserfindByUserName(String userName);UserfindByUserNameOrEmail(String username,String email);}

9.6 启动类

packagecom.example.springbootmultijpa;importorg.springframework.boot.SpringApplication;importorg.springframework.boot.autoconfigure.SpringBootApplication;@SpringBootApplicationpublicclassSpringBootMultiJpaApplication{publicstaticvoidmain(String[] args){SpringApplication.run(SpringBootMultiJpaApplication.class, args);}}

9.7 测试

packagecom.example.springbootmultijpa.repository;importcom.example.springbootmultijpa.model.User;importcom.example.springbootmultijpa.repository.test1.UserTest1Repository;importcom.example.springbootmultijpa.repository.test2.UserTest2Repository;importorg.junit.Test;importorg.junit.runner.RunWith;importorg.springframework.boot.test.context.SpringBootTest;importorg.springframework.test.context.junit4.SpringRunner;importjavax.annotation.Resource;importjava.text.DateFormat;importjava.util.Date;@RunWith(SpringRunner.class)@SpringBootTestpublicclassUserRepositoryTests{@ResourceprivateUserTest1Repository userTest1Repository;@ResourceprivateUserTest2Repository userTest2Repository;@TestpublicvoidtestSave()throwsException{Date date =newDate();DateFormat dateFormat =DateFormat.getDateTimeInstance(DateFormat.LONG,DateFormat.LONG);String formattedDate = dateFormat.format(date);
        userTest1Repository.save(newUser("aa","aa123456","[email protected]","aa", formattedDate));
        userTest1Repository.save(newUser("bb","bb123456","[email protected]","bb", formattedDate));
        userTest2Repository.save(newUser("cc","cc123456","[email protected]","cc", formattedDate));}@TestpublicvoidtestDelete()throwsException{
        userTest1Repository.deleteAll();
        userTest2Repository.deleteAll();}@TestpublicvoidtestBaseQuery(){Date date =newDate();DateFormat dateFormat =DateFormat.getDateTimeInstance(DateFormat.LONG,DateFormat.LONG);String formattedDate = dateFormat.format(date);User user =newUser("ff","ff123456","[email protected]","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：

运行

testBaseQuery()

得到的结果：

运行

testDelete()

得到的结果：