pom.xml

--dependencygroupIdorg.springframework.boot/groupIdartifactIdspring-boot-starter/artifactId/dependency

dependencygroupIdorg.springframework.boot/groupIdartifactIdspring-boot-starter-data-jpa/artifactId/dependency

/dependencies

{SpringApplication.run(SpringMainApplication.class,

args);}

注意多个数据库应该具有相同的驱动程序。

无法连接到不同的数据库如

MySql

3.支持多个数据库来模拟各种自动化测试场景。

不同数据库可能具有不同的配置和静态信息意味着你可以用一个自动化测试脚本覆盖多个测试用例。

4.在同一个应用程序中支持多个组织。

根据用户登录可以动态决定他们的数据应进入哪个组织的数据库。

5.一次性为多个数据库插入数据。

例如你有一个从脚本创建数据的批处理作业你可以一次性连接到多个数据库并对所有这些数据库运行脚本而无需指向不同的应用程序或重新启动服务器来执行此操作。

多数据源示意图如下

--dependencygroupIdorg.springframework.boot/groupIdartifactIdspring-boot-starter/artifactId/dependencydependencygroupIdorg.springframework.boot/groupIdartifactIdspring-boot-starter-actuator/artifactId/dependencydependencygroupIdorg.springframework.boot/groupIdartifactIdspring-boot-devtools/artifactId/dependencydependencygroupIdorg.springframework.boot/groupIdartifactIdspring-boot-starter-data-jpa/artifactId/dependencydependencygroupIdorg.springframework.boot/groupIdartifactIdspring-boot-starter-web/artifactId/dependency!--

Swagger

--dependencygroupIdio.springfox/groupIdartifactIdspringfox-swagger2/artifactIdversion2.9.2/version/dependencydependencygroupIdio.springfox/groupIdartifactIdspringfox-swagger-ui/artifactIdversion2.9.2/version/dependency!--

lombok

--dependencygroupIdorg.projectlombok/groupIdartifactIdlombok/artifactIdversion1.18.12/versionscopeprovided/scope/dependency!--

Database

--dependencygroupIdorg.postgresql/groupIdartifactIdpostgresql/artifactId/dependency!--

test

--dependencygroupIdorg.springframework.boot/groupIdartifactIdspring-boot-starter-test/artifactIdscopetest/scopeexclusionsexclusiongroupIdorg.junit.vintage/groupIdartifactIdjunit-vintage-engine/artifactId/exclusion/exclusions/dependency/dependenciesdependencyManagementdependenciesdependencygroupIdorg.springframework.cloud/groupIdartifactIdspring-cloud-starter-parent/artifactIdversion${spring-cloud-dependencies.version}/versiontypepom/typescopeimport/scope/dependencydependencygroupIdorg.springframework.cloud/groupIdartifactIdspring-cloud-gcp-dependencies/artifactIdversion${project.version}/versiontypepom/typescopeimport/scope/dependency/dependencies/dependencyManagementbuildpluginsplugingroupIdorg.springframework.boot/groupIdartifactIdspring-boot-maven-plugin/artifactId/pluginplugingroupIdorg.apache.maven.plugins/groupIdartifactIdmaven-surefire-plugin/artifactId/plugin/plugins/build

第二步添加数据库连接配置

app.datasource.db1.jdbc-urljdbc:postgresql://db1.com:5432/dbname1

app.datasource.db1.usernamepostgres

app.datasource.db1.passwordpasswordapp.datasource.db2.jdbc-urljdbc:postgresql://db2.com:5432/dbname2

app.datasource.db2.usernamepostgres

app.datasource.db2.passwordpasswordapp.datasource.db3.jdbc-urljdbc:postgresql://db3.com:5432/dbname3

app.datasource.db3.usernamepostgres

app.datasource.db3.passwordpassword

PostgresSQL

{SpringApplication.run(MultidatabaseApplication.class,

args);}

EnableJpaRepositories(entityManagerFactoryRef

multiEntityManager,transactionManagerRef

EntityScan(com.sample.client.repositories.dto.entity)

public

com.sample.client.repositories.dto.entity;//

db1DataSource)ConfigurationProperties(app.datasource.db1)public

DataSource

DataSourceBuilder.create().type(HikariDataSource.class).build();}//db2连接数据源注入Bean(name

db2DataSource)ConfigurationProperties(app.datasource.db2)public

DataSource

DataSourceBuilder.create().type(HikariDataSource.class).build();}//db3连接数据源注入Bean(name

db3DataSource)ConfigurationProperties(app.datasource.db3)public

DataSource

DataSourceBuilder.create().type(HikariDataSource.class).build();}//多数据源配置Bean(name

DataSource

HashMap();targetDataSources.put(ClientNames.DB1,

db1DataSource());targetDataSources.put(ClientNames.DB2,

db2DataSource());targetDataSources.put(ClientNames.DB3,

db3DataSource());MultiRoutingDataSource

new

MultiRoutingDataSource();multiRoutingDataSource.setDefaultTargetDataSource(db1DataSource());multiRoutingDataSource.setTargetDataSources(targetDataSources);return

multiRoutingDataSource;}//多实体配置代码Bean(name

LocalContainerEntityManagerFactoryBean

multiEntityManager()

{LocalContainerEntityManagerFactoryBean

new

LocalContainerEntityManagerFactoryBean();em.setDataSource(multiRoutingDataSource());em.setPackagesToScan(PACKAGE_SCAN);HibernateJpaVendorAdapter

vendorAdapter

HibernateJpaVendorAdapter();em.setJpaVendorAdapter(vendorAdapter);em.setJpaProperties(hibernateProperties());return

em;}Bean(name

JpaTransactionManager();transactionManager.setEntityManagerFactory(multiEntityManager().getObject());return

transactionManager;}PrimaryBean(nameentityManagerFactory)public

dbSessionFactory()

LocalSessionFactoryBean();sessionFactoryBean.setDataSource(multiRoutingDataSource());sessionFactoryBean.setPackagesToScan(PACKAGE_SCAN);sessionFactoryBean.setHibernateProperties(hibernateProperties());return

hibernate

Properties();properties.put(hibernate.show_sql,

true);properties.put(hibernate.format_sql,

true);properties.put(hibernate.dialect,

org.hibernate.dialect.PostgreSQLDialect);properties.put(hibernate.id.new_generator_mappings,

false);properties.put(hibernate.jdbc.lob.non_contextual_creation,

true);return

com.sample.client.repositories.dto.entity

此目录包含

MultiRoutingDataSource类是我们的实际实现允许我们连接到多个数据库

接下来我们还需要一个DBContextHolder类来保存数据库引用并在运行时动态更改数据库。

public

{contextHolder.set(dbType);}public

static

接下来我们需要对MultiRoutingDataSource进行重写

public

DBContextHolder.getCurrentDb();}

RestController

clientMasterService;GetMapping(/{clientdb})public

String

clientMasterService.getClientNames(clientdbName);}

Service

db1:DBContextHolder.setCurrentDb(ClientNames.DB1);break;case

db2:DBContextHolder.setCurrentDb(ClientNames.DB2);break;case

db3:DBContextHolder.setCurrentDb(ClientNames.DB3);break;}Entity1

clientMasterRepository.findByEntity1Name(John

Doe);if(e1

ClientMasterService使用DBContextHolder类根据从

Rest

如果你有多租户需求或者多环境测试需求等可以自己尝试编写一个多数据源框架也可以引入第三方库来解决此需求。