Spring JPA Specify entity's table name on the repository interface - spring-boot

Question

I have a scenario where I want to create multiple repositories for the same entity class.
The first and simplest scenario I want to save some of the instances of my class as rows in a different table than the primary table (which is designated on the entity itself).
other scenarios would be to create remote back ups hence the whole datasource would be different.
Does Spring allow things like that?

Answer 1

I'm not sure you'll want this, but here it is anyway... The best I could find using Spring Data Repositories is the following:
(1a) Manually define 2 repository beans to use 2 datasources:
#Bean
#Qualifier("db1")
public ModelJpaRepository modelJpaRepositoryDb1() {
JpaRepositoryFactoryBean<ModelJpaRepository, Model, String> myFactory = new JpaRepositoryFactoryBean<ModelJpaRepository, Model, String>();
myFactory.setRepositoryInterface(ModelJpaRepository.class);
myFactory.setEntityManager(entityManagerFactory1().createEntityManager());
myFactory.afterPropertiesSet();
return myFactory.getObject();
}
#Bean
#Qualifier("db2")
public ModelJpaRepository modelJpaRepositoryDb2() {
JpaRepositoryFactoryBean<ModelJpaRepository, Model, String> myFactory = new JpaRepositoryFactoryBean<ModelJpaRepository, Model, String>();
myFactory.setRepositoryInterface(ModelJpaRepository.class);
myFactory.setEntityManager(entityManagerFactory2().createEntityManager());
myFactory.afterPropertiesSet();
return myFactory.getObject();
}
(1b): Define the 2 datasources (referred to by the previous repository definitions):
#Bean(name = "dataSource1")
public DataSource dataSource1() {
BasicDataSource bds = new BasicDataSource();
bds.setDriverClassName(...);
bds.setUrl(...);
bds.setUsername(...);
bds.setPassword(...);
return bds;
}
#Bean(name = "dataSource2")
public DataSource dataSource2() {
BasicDataSource bds = new BasicDataSource();
bds.setDriverClassName(...);
bds.setUrl(...);
bds.setUsername(...);
bds.setPassword(...);
return bds;
}
(1c): Define 2 entityManagers - 1 per datasource (referred to by the previous repository definitions):
#Bean
public EntityManagerFactory entityManagerFactory1() {
LocalContainerEntityManagerFactoryBean entityManagerFactory = new LocalContainerEntityManagerFactoryBean();
entityManagerFactory.setDataSource(dataSource1());
entityManagerFactory.setPersistenceUnitName("pu1");
entityManagerFactory.setJpaVendorAdapter(jpaVendorAdapter());
entityManagerFactory.setJpaProperties(jpaProperties());
entityManagerFactory.afterPropertiesSet();
return entityManagerFactory.getNativeEntityManagerFactory();
}
#Bean
public EntityManagerFactory entityManagerFactory2() {
LocalContainerEntityManagerFactoryBean entityManagerFactory = new LocalContainerEntityManagerFactoryBean();
entityManagerFactory.setDataSource(dataSource2());
entityManagerFactory.setPersistenceUnitName("pu2");
entityManagerFactory.setJpaVendorAdapter(jpaVendorAdapter());
entityManagerFactory.setJpaProperties(jpaProperties());
entityManagerFactory.afterPropertiesSet();
return entityManagerFactory.getNativeEntityManagerFactory();
}
(2) Inject the 2 repositories and use them:
#Autowired
#Qualifier("db1")
private ModelJpaRepository modelJpaRepositoryDb1;
#Autowired
#Qualifier("db2")
private ModelJpaRepository modelJpaRepositoryDb2;
...
modelJpaRepositoryDb1.save(model);
modelJpaRepositoryDb2.save(model);
(3) Define the "OtherModel" and include the "Model" as embedded:
#Entity
#Table(name = "OTHER_TABLE")
public class OtherTable {
#Id
#Column(name = "ID", nullable = false)
private long id;
#Embedded
private Model model;
public OtherTable(Model model) {
this.model = model;
this.id = model.getId();
}
}
For info, This answer suggests using #Inheritance(strategy=InheritanceType.TABLE_PER_CLASS), to achieve define an additional model (inheritance vs composition).
(4) Define the 2 repositories for the OtherTable:
#Bean
#Qualifier("db1")
public OtherTableJpaRepository otherTableJpaRepositoryDb1() {
JpaRepositoryFactoryBean<OtherTableJpaRepository, OtherTable, String> myFactory = new JpaRepositoryFactoryBean<OtherTableJpaRepository, OtherTable, String>();
myFactory.setRepositoryInterface(OtherTableJpaRepository.class);
myFactory.setEntityManager(entityManagerFactory1().createEntityManager());
myFactory.afterPropertiesSet();
return myFactory.getObject();
}
#Bean
#Qualifier("db2")
public OtherTableJpaRepository otherTableJpaRepositoryDb2() {
JpaRepositoryFactoryBean<OtherTableJpaRepository, OtherTable, String> myFactory = new JpaRepositoryFactoryBean<OtherTableJpaRepository, OtherTable, String>();
myFactory.setRepositoryInterface(OtherTableJpaRepository.class);
myFactory.setEntityManager(entityManagerFactory2().createEntityManager());
myFactory.afterPropertiesSet();
return myFactory.getObject();
}
(5) Inject and use them all:
#Autowired
#Qualifier("db1")
private ModelJpaRepository modelJpaRepositoryDb1;
#Autowired
#Qualifier("db2")
private ModelJpaRepository modelJpaRepositoryDb2;
#Autowired
#Qualifier("db1")
private OtherTableJpaRepository otherTableJpaRepositoryDb1;
#Autowired
#Qualifier("db2")
private OtherTableJpaRepository otherTableJpaRepositoryDb2;
// ...
modelJpaRepositoryDb1.save(model);
otherTableJpaRepositoryDb1.save(new OtherTable(model));
modelJpaRepositoryDb2.save(model);
otherTableJpaRepositoryDb2.save(new OtherTable(model));