问题
Grails has a multi-tenancy plugin for a single database and a multi-tenancy plugin for multi-databases, but the one for multi-databases is no longer supported/maintained. Is there some way I can instead use Spring or Hibernate themselves for a multi-tenancy multi-database Grails application?
回答1:
You can use Hibernate multitenancy described here http://docs.jboss.org/hibernate/orm/4.3/devguide/en-US/html/ch16.html
OR
You can also consider Spring's AbstractRoutingDataSource
The general idea is that a routing DataSource acts as an intermediary - while the ‘real’ DataSource can be determined dynamically at runtime based upon a lookup key.
https://spring.io/blog/2007/01/23/dynamic-datasource-routing/
You can find a newer post, giving an exemplary use with hibernate, the gist of the solution you can find in the following two snippets
public class MyRoutingDataSource extends AbstractRoutingDataSource{
@Override
protected Object determineCurrentLookupKey() {
String language = LocaleContextHolder.getLocale().getLanguage();
System.out.println("Language obtained: "+ language);
return language;
}
}
the return value will be used as a discriminator for a datasource, the following configuration sets the mapping
<bean id="dataSource" class="com.howtodoinjava.controller.MyRoutingDataSource">
<property name="targetDataSources">
<map key-type="java.lang.String">
<entry key="en" value-ref="concreteDataSourceOne"/>
<entry key="es" value-ref="concreteDataSourceTwo"/>
</map>
</property>
</bean>
回答2:
In our case we use LocalContainerEntityManagerFactoryBean where we create a multiTenantMySQLProvider.
<bean class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean" id="entityManagerFactory">
<property name="dataSource" ref="dataSource"/>
<property name="jpaVendorAdapter">
<bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter" />
</property>
<property name="packagesToScan" value="domain"/>
<property name="jpaPropertyMap">
<map>
<entry key="hibernate.dialect" value="org.hibernate.dialect.MySQL5Dialect" />
<entry key="javax.persistence.jdbc.driver" value="org.mariadb.jdbc.Driver" />
<entry key="hibernate.show_sql" value="false" />
<entry key="hibernate.multiTenancy" value="SCHEMA" />
<entry key="hibernate.multi_tenant_connection_provider" value-ref="mySQLMultiTenantConnectionProvider" />
<entry key="hibernate.tenant_identifier_resolver" value-ref="tenantIdentifierResolver" />
</map>
</property>
</bean>
<bean id="tenantService"
class="multitenancy.service.impl.TenantServiceImpl">
<property name="defaultTenantId" value="${multitenancy.defaultTenantId}" />
<property name="ldapTemplate" ref="ldapTemplate" />
</bean>
<bean id="connectionProvider"
class="multitenancy.hibernate.ConnectionProviderImpl" lazy-init="false">
<property name="dataSource" ref="dataSource" />
</bean>
<bean id="mySQLMultiTenantConnectionProvider"
class="multitenancy.hibernate.MySQLMultiTenantConnectionProviderImpl" lazy-init="false">
<property name="connectionProvider" ref="connectionProvider" />
<property name="tenantIdentifierForAny" value="${multitenancy.tenantIdentifierForAny}" />
<property name="schemaPrefix" value="${multitenancy.schemaPrefix}" />
</bean>
<bean id="tenantIdentifierResolver"
class="multitenancy.hibernate.TenantIdentifierResolverImpl" lazy-init="false">
<property name="tenantService" ref="tenantService" />
</bean>
<bean id="tenantIdentifierSchedulerResolver"
class="security.impl.TenantIdentifierSchedulerResolverImpl" lazy-init="false">
<property name="ldapTemplate" ref="ldapTemplate" />
</bean>
And here the implementation of the MySQLMultiTenantConnectionProviderImpl
public class MySQLMultiTenantConnectionProviderImpl implements MultiTenantConnectionProvider, ServiceRegistryAwareService, Stoppable {
private static final Logger LOGGER = LoggerFactory.getLogger(MySQLMultiTenantConnectionProviderImpl.class);
@Setter
private ConnectionProvider connectionProvider;
@Setter
private String tenantIdentifierForAny;
@Setter
private String schemaPrefix;
@Override
public Connection getAnyConnection() throws SQLException {
return connectionProvider.getConnection();
}
@Override
public void releaseAnyConnection(Connection connection) throws SQLException {
connectionProvider.closeConnection( connection );
}
@Override
public Connection getConnection(String tenantIdentifier) throws SQLException {
final Connection connection = getAnyConnection();
String schema = schemaPrefix + tenantIdentifier;
try {
LOGGER.debug("setting schema in DB Connection : {}" , schema);
connection.createStatement().execute( "USE " + schema );
}
catch ( SQLException e ) {
throw new HibernateException(
"Could not alter JDBC connection to specified schema [" + schema + "]", e
);
}
return connection;
}
@Override
public void releaseConnection(String tenantIdentifier, Connection connection) throws SQLException {
try {
connection.createStatement().execute( "USE " + tenantIdentifierForAny );
}
catch ( SQLException e ) {
LOGGER.error(" error on releaseConnection. The connection will be not closed. SQLException : {}" , e);
// on error, throw an exception to make sure the connection is not returned to the pool.
throw new HibernateException(
"Could not alter JDBC connection to specified schema [" + tenantIdentifier + "]", e
);
}
// I follow the hibernate recommendation and we don't return the connetion to the pool.
connectionProvider.closeConnection( connection );
}
@Override
public boolean supportsAggressiveRelease() {
return true;
}
@Override
public void stop() {
}
@Override
public boolean isUnwrappableAs(Class unwrapType) {
return ConnectionProvider.class.equals( unwrapType ) ||
MultiTenantConnectionProvider.class.equals( unwrapType ) ||
AbstractMultiTenantConnectionProvider.class.isAssignableFrom( unwrapType );
}
@Override
public <T> T unwrap(Class<T> unwrapType) {
if ( isUnwrappableAs( unwrapType ) ) {
return (T) this;
}
throw new UnknownUnwrapTypeException( unwrapType );
}
@Override
public void injectServices(ServiceRegistryImplementor serviceRegistry) {
}
}
回答3:
This is how I use hibernate multitenancy with SCHEMA approach. May be it will be helpful for you.
applicationContext.xml
...
<bean id="multiTenantConnectionProvider" class="org.myapp.MyAppMultiTenantConnectionProvider"/>
<bean id="sessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
<property name="packagesToScan" value="org.myapp.entities"/>
<property name="multiTenantConnectionProvider" ref="multiTenantConnectionProvider"/>
<property name="hibernateProperties">
<props>
<prop key="hibernate.multiTenancy">SCHEMA</prop>
<prop key="hibernate.tenant_identifier_resolver">org.myapp.MyAppTenantIdentifierResolver</prop>
...
</props>
</property>
</bean>
...
MyAppMultiTenantConnectionProvider.java
public class MyAppMultiTenantConnectionProvider implements MultiTenantConnectionProvider {
@Override
public Connection getConnection(String tenantIdentifier) throws SQLException {
//This is where your tenant resolving logic will be implemented
return MyMultitenantConnectionPool.getConnection(tenantIdentifier);
}
}
MyAppTenantIdentifierResolver.java
public class MyAppTenantIdentifierResolver implements CurrentTenantIdentifierResolver {
@Override
public String resolveCurrentTenantIdentifier() {
/*
This is where you determine which tenant to use.
In this app SpringSecurity used for this purpose.
TenantUser class extends org.springframework.security.core.userdetails.User with tenant information.
*/
Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
if (authentication == null || !authentication.isAuthenticated()) return "";
if (authentication.getPrincipal() instanceof TenantUser) {
TenantUser user = (TenantUser) authentication.getPrincipal();
return user.getTenant();
} else return "";
}
@Override
public boolean validateExistingCurrentSessions() {
return false;
}
}
来源：https://stackoverflow.com/questions/30054988/spring-or-hibernate-multi-tenancy-for-multi-database-grails-app