Spring Boot - connecting to two schema per tenant - spring-boot

Question

I am creating a Spring boot Multimodule application in which one of the module has unique requirement. The module should be able to connect to one fixed schema say S1 and there are two other schema S2 and S3.
Depending upon the region it will connect to S1 and S2 or S1 and S3.
Will I have to follow the multi tenancy approach here ?
If yes how do I use multi tenancy to connect to two schema for a particular request ?

Answer 1

As per my understanding you want to connect to different DB's based on country. I have similar kind of issue in my project.
My requirement is when there is a json request i need to fetch country code from that and based on that i'll connect to that country specific DB. Below is my code. Hope this helps you.
application.properties
spring.main.web-application-type=none
#spring.main.allow-bean-definition-overriding=true
#au DB connection
spring.datasource.au.url=
spring.datasource.au.username=
spring.datasource.au.password=
#cn DB connection
spring.datasource.cn.url=
spring.datasource.cn.username=
spring.datasource.cn.password=
spring.jpa.show-sql=true
spring.jpa.database=default
spring.jpa.hibernate.ddl-auto=none
spring.jpa.hibernate.naming.implicit-strategy=org.hibernate.boot.model.naming.ImplicitNamingStrategyLegacyHbmImpl
spring.jpa.hibernate.naming.physical-strategy=org.springframework.boot.orm.jpa.hibernate.SpringPhysicalNamingStrategy
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL5InnoDBDialect
DB configuration
For Au :
Here i'm using #Primary annotation for AU.
#Configuration
#EnableJpaRepositories(entityManagerFactoryRef = "auEntityManagerFactory", transactionManagerRef = "auTransactionManager", basePackages = "com.dbs.multiDb.au.repository")
#EnableTransactionManagement
public class auDsConfig {
Logger logger = LogManager.getLogger(this.getClass());
#Autowired
Environment env;
#Bean(name = "auEntityManagerFactory")
#Primary
public LocalContainerEntityManagerFactoryBean cnEntityManagerFactory(final EntityManagerFactoryBuilder builder,
final #Qualifier("au-db") DataSource dataSource) {
return builder.dataSource(dataSource).packages("com.dbs.multiDb.domain").persistenceUnit("auDb")
.properties(singletonMap("hibernate.hbm2ddl.auto", "none")).build();
}
#Bean(name = "auTransactionManager")
#Primary
public PlatformTransactionManager auTransactionManager(
#Qualifier("auEntityManagerFactory") EntityManagerFactory cnEntityManagerFactory) {
return new JpaTransactionManager(cnEntityManagerFactory);
}
#SuppressWarnings("unused")
#Bean(name = "au-db")
#Primary
#ConfigurationProperties(prefix = "spring.datasource.au")
public DataSource auDataSource() {
DriverManagerDataSource dbFinal = new DriverManagerDataSource();
dbFinal.setDriverClassName(env.getProperty("jdbc.driverClassName"));
dbFinal.setUrl(env.getProperty("spring.datasource.au.url"));
dbFinal.setUsername(env.getProperty("spring.datasource.au.username"));
dbFinal.setPassword(env.getProperty("spring.datasource.au.password"));
return dbFinal;
}
}
CN DB config :
#Configuration
#EnableJpaRepositories(entityManagerFactoryRef = "cnEntityManagerFactory", transactionManagerRef = "cnTransactionManager", basePackages = "com.dbs.multiDb.cn.repository")
#EnableTransactionManagement
public class cnDsConfig {
#Bean(name = "cnEntityManagerFactory")
public LocalContainerEntityManagerFactoryBean cnEntityManagerFactory(final EntityManagerFactoryBuilder builder,
final #Qualifier("cn-db") DataSource dataSource) {
return builder.dataSource(dataSource).packages("com.dbs.multiDb.domain").persistenceUnit("cnDb")
.properties(singletonMap("hibernate.hbm2ddl.auto", "none")).build();
}
#Bean(name = "cnTransactionManager")
public PlatformTransactionManager cnTransactionManager(
#Qualifier("cnEntityManagerFactory") EntityManagerFactory cnEntityManagerFactory) {
return new JpaTransactionManager(cnEntityManagerFactory);
}
#Bean(name = "cn-db")
#ConfigurationProperties(prefix = "spring.datasource.cn")
public DataSource cnDataSource() {
DriverManagerDataSource dbFinal = new DriverManagerDataSource();
dbFinal.setDriverClassName(env.getProperty("jdbc.driverClassName"));
dbFinal.setUrl(env.getProperty("spring.datasource.cn.url"));
dbFinal.setUsername(env.getProperty("spring.datasource.cn.username"));
dbFinal.setPassword(env.getProperty("spring.datasource.cn.password"));
return dbFinal;
}
}
Created REPO's for both countries :
AU Repo :
#Repository
public interface AURepository extends CrudRepository<BeanName,String>{
}
CN Repo :
#Repository
public interface CNRepository extends CrudRepository<BeanName,String>{
}
Service class :
#Service
public class ServiceClass{
private AURepository auTxn;
private CNRepository cnTxn;
#Autowired
public ServiceClass(AURepository auTxn, CNRepository cnTxn) {
super();
this.auTxn = auTxn;
this.cnTxn = cnTxn;
}
public List<Bean> getData(String input, String country) {
List<Bean> data= new ArrayList<Bean>();
//If this is AU then it will connect to AU DB and retrieve data.
if (country.equals("AU")) {
data= auTxn.findall();
}
//If this is CN then it will connect to AU DB and retrieve data.
else if (country.equals("CN")) {
data= cnTxn.findall();
}
return data;
}
}