Springboot 之 JPA 多数据源实现

简介

微服务提倡单服务单数据库；但是，一个微服务连接多个数据库是不可避免的。今天，我将介绍如何使用它 JPA 多数据源。主要使用不同数据库 Repository 接口分别存储在不同的接口中 package，Spring 扫描不同的包，注入不同的数据源来实现多数据源。

学生表 t_student

CREATE TABLE `t_student` (`id`  int(11) NOT NULL AUTO_INCREMENT ,`user_name`  varchar(64) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL ,`sex`  int(1) NULL DEFAULT NULL ,`grade`  varchar(64) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL ,PRIMARY KEY (`id`))ENGINE=InnoDBDEFAULT CHARACTER SET=utf8 COLLATE=utf8_general_ciAUTO_INCREMENT=1 ROW_FORMAT=DYNAMIC;

教师表 t_teacher

CREATE TABLE `t_teacher` (`id`  int(11) NOT NULL AUTO_INCREMENT ,`user_name`  varchar(64) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL ,`sex`  int(1) NULL DEFAULT NULL ,`office`  varchar(64) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL ,PRIMARY KEY (`id`))ENGINE=InnoDBDEFAULT CHARACTER SET=utf8 COLLATE=utf8_general_ciAUTO_INCREMENT=1 ROW_FORMAT=DYNAMIC;

<project xmlns="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 http://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>com.olive</groupId><artifactId>jpa-multip-datasource</artifactId><version>0.0.1-SNAPSHOT</version><packaging>jar</packaging><name>jpa-multip-datasource</name><url>http://maven.apache.org</url><parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>2.5.14</version><relativePath /> <!-- lookup parent from repository --></parent><properties><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding><maven.compiler.source>8</maven.compiler.source><maven.compiler.target>8</maven.compiler.target></properties><dependencies><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><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId></dependency></dependencies></project>

第一个主数据源分别是第一个(primary)，第二数据源(second)，具体配置如下：

# server基本配置:  port: 8080# Spring数据库:  jpa:    show-sql: true    database-platform: org.hibernate.dialect.MySQL5InnoDBDialect    hibernate:      ddl-auto: update  datasource:    primary:      driver-class-name: com.mysql.jdbc.Driver      jdbc-url: jdbc:mysql://127.0.0.1:3306/db01?characterEncoding=utf-8&allowMultiQueries=true&autoReconnect=true      username: root      password: root    sencond:      driver-class-name: com.mysql.cj.jdbc.Driver      jdbc-url: jdbc:mysql://127.0.0.1:3306/db02?characterEncoding=utf-8&allowMultiQueries=true&autoReconnect=true      username: root      password: root  jackson:    serialization:      indent-output: true

DataSourceConfig 配置

/** * @Description: 数据源配置 */@Configurationpublic class DataSourceConfig {    @Bean(name = "primaryDataSource")    @Qualifier("primaryDataSource")    @ConfigurationProperties(prefix = "spring.datasource.primary")    @Primary    public DataSource primaryDataSource() {        return DataSourceBuilder.create().build();    }    @Bean(name = "secondDataSource")    @Qualifier("secondDataSource")    @ConfigurationProperties(prefix = "spring.datasource.sencond")    public DataSource secondDataSource() {        return DataSourceBuilder.create().build();    }}

Config数据源Primary

/** * @Description: 主数据源配置 * @date */@Configuration@EnableTransactionManagement@EnableJpaRepositories(entityManagerFactoryRef = "entityManagerFactoryPrimary",                        transactionManagerRef = "transactionManagerPrimary",                        basePackages = {"com.olive.repository.primary"})public class PrimaryConfig {    @Autowired    @Qualifier("primaryDataSource")    private DataSource primaryDataSource;    @Autowired    private HibernateProperties hibernateProperties;    @Autowired    private JpaProperties jpaProperties;    @Primary    @Bean(name = "entityManagerPrimary")    public EntityManager entityManager(EntityManagerFactoryBuilder builder) {        return entityManagerFactoryPrimary(builder).getObject().createEntityManager();    }    @Primary    @Bean(name = "entityManagerFactoryPrimary")    //primary实体工厂    public LocalContainerEntityManagerFactoryBean entityManagerFactoryPrimary (EntityManagerFactoryBuilder builder) {        return builder.dataSource(primaryDataSource)                .properties(getHibernateProperties())                .packages("com.olive.entity.primary")     ////换成你自己的实体类的位置                .persistenceUnit("primaryPersistenceUnit")                .build();    }    @Primary    @Bean(name = "transactionManagerPrimary")    public PlatformTransactionManager transactionManager(EntityManagerFactoryBuilder builder) {        return new JpaTransactionManager(entityManagerFactoryPrimary(builder).getObject());    }    private Map<String, Object> getHibernateProperties() {        return hibernateProperties.determineHibernateProperties(jpaProperties.getProperties(), new HibernateSettings());    }}

SecondConfig 数据源源

/** * @Description: 第二个数据源配置 */@Configuration@EnableTransactionManagement@EnableJpaRepositories(entityManagerFactoryRef = "entityManagerFactorySecond",                        transactionManagerRef = "transactionManagerSecond",                        basePackages = {"com.olive.repository.second"})public class SecondConfig {    @Autowired    @Qualifier("secondDataSource")    private DataSource secondDataSource;    @Resource    private JpaProperties jpaProperties;    @Resource    private HibernateProperties hibernateProperties;    @Bean(name = "entityManagerSecond")    public EntityManager entityManager(EntityManagerFactoryBuilder builder) {        return entityManagerFactorySecond(builder).getObject().createEntityManager();    }    @Bean(name = "entityManagerFactorySecond")    //primary实体工厂    public LocalContainerEntityManagerFactoryBean entityManagerFactorySecond (EntityManagerFactoryBuilder builder) {        return builder.dataSource(secondDataSource)                .properties(getHibernateProperties())                .packages("com.olive.entity.second")     ////换成你自己的实体类的位置                .persistenceUnit("secondaryPersistenceUnit")                .build();    }    @Bean(name = "transactionManagerSecond")    public PlatformTransactionManager transactionManager(EntityManagerFactoryBuilder builder) {        return new JpaTransactionManager(entityManagerFactorySecond(builder).getObject());    }    private Map<String, Object> getHibernateProperties() {        return hibernateProperties.determineHibernateProperties(jpaProperties.getProperties(), new HibernateSettings());    }}

Student实体类

package com.olive.entity.primary;import java.io.Serializable;import javax.persistence.Column;import javax.persistence.Entity;import javax.persistence.GeneratedValue;import javax.persistence.GenerationType;import javax.persistence.Id;import lombok.Data;@Data@Entity(name="t_student")public class StudentDO implements Serializable{    @Id    @GeneratedValue(strategy = GenerationType.IDENTITY)    private Long id;    @Column(name = "user_name") // 若实体属性与表字段名称一致，不需要添加@Column注释    private String name;    @Column(name = "sex")    private int sex;        @Column(name = "grade")    private String grade;}

Teacher实体类

package com.olive.entity.second;import java.io.Serializable;import javax.persistence.Column;import javax.persistence.Entity;import javax.persistence.GeneratedValue;import javax.persistence.GenerationType;import javax.persistence.Id;import lombok.Data;@Data@Entity(name="t_teacher")public class TeacherDO implements Serializable {@Id@GeneratedValue(strategy = GenerationType.IDENTITY)private Long id;@Column(name = "user_name") // 若实体属性与表字段名称一致，无需添加@Column注释privatete String name;@Column(name = "sex")private int sex;@Column(name = "office")private String office;}

Studentrepositor

package com.olive.repository.primary;import org.springframework.data.jpa.repository.JpaRepository;import org.springframework.stereotype.Repository;import com.olive.entity.primary.StudentDO;@Repositorypublic interface StudentRepository extends JpaRepository<StudentDO, Long> {}

Teacherrepositor

package com.olive.repository.second;import org.springframework.data.jpa.repository.JpaRepository;import org.springframework.stereotype.Repository;import com.olive.entity.second.TeacherDO;@Repositorypublic interface TeacherRepository extends JpaRepository<TeacherDO, Long> {}

package com.olive;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;@SpringBootApplicationpublic class Application {    public static void main(String[] args) {        SpringApplication.run(Application.class);    }}

package com.olive;import org.junit.jupiter.api.Test;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.boot.test.context.SpringBootTest;import com.olive.entity.primary.StudentDO;import com.olive.entity.second.TeacherDO;import com.olive.repository.primary.StudentRepository;import com.olive.repository.second.TeacherRepository;@SpringBootTestpublic class JpaTest {@AutowiredStudentRepository studentRepository;@AutowiredTeacherRepository teacherRepository;@Testpublic void userSave() {StudentDO studentDO = new StudentDO();studentDO.setName(“BUG弄潮儿”);studentDO.setSex(1);studentDO.setGrade(一年级);studentRepository.save(studentDO);TeacherDO teacherDO = new TeacherDO();teacherDO.setName(Java乐园);teacherDO.setSex(2);teacherDO.setOffice(语文);teacherRepository.save(teacherDO);}}