Hibernate multi-tenancy create schema during runtime

Question

I am setting up multi-tenant support for a java web application using hibernate 4 and spring 4. The default schema is created and set when the application starts. This schem

Answer 1

you can sole your problem by using eclipseLink. here's some util links: https://wiki.eclipse.org/EclipseLink/Examples/JPA/Multitenant and http://www.javacodegeeks.com/2012/02/sneak-peak-at-java-ee-7-multitenant.html or if you want to use hibernate you can take a look at this: http://docs.jboss.org/hibernate/orm/4.1/devguide/en-US/html/ch16.html and this example on multi tenancy on hibernate : https://gist.github.com/dipold/5700724 and http://www.devx.com/Java/Article/47817

Answer 2

I came up with a solution that solves my problem. I hope it is useful to someone out there.

So the main problem came down to the Hibernate restriction of creating a schema for a new client during runtime while in multi-tenant configuration.

"Hibernate does not support automatic schema export in a multi-tenancy environment."

My solution to get around this restriction (using Spring) was to create a new LocalSessionFactoryBean that is configured to NOT to support multi-tenancy. So basically I have two LocalSessionFactoryBeans.

1. Multi-Tenant LocalSessionFactoryBean that is used for multi-tenant sessions
2. Non Multi-Tenant LocalSessionFactoryBean that is used to create schemas for tenants using the configuration set in the spring file.

Spring configuration

<!-- Multi-tenant SessionFactory -->
<bean id="sessionFactory"
    class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
    <property name="dataSource" ref="dataSource" />
    <property name="hibernateProperties">
        <map>
            <entry key="hibernate.dialect" value="${hibernate.dialect}" />
            <entry key="hibernate.hbm2ddl.auto" value="NONE" />
            <!-- Multi-tenancy support -->
            <entry key="hibernate.multiTenancy" value="SCHEMA" />
            <entry key="hibernate.tenant_identifier_resolver" value="${hibernate.tenant_identifier_resolver}" />
            <entry key="hibernate.multi_tenant_connection_provider" value-ref="multiTenantConnectionProvider" />
        </map>
    </property>
    <property name="mappingResources">
        <list>
            <COMMON SCHEMA MAPPING RESOURCES />
        </list>
    </property>
</bean>

<!-- SessionFactory capable of managing multi-tenant schemas -->
<bean id="sessionFactorySchemaManager"
    class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
    <property name="dataSource" ref="dataSource" />
    <property name="hibernateProperties">
        <map>
            <entry key="hibernate.dialect" value="${hibernate.dialect}" />
            <entry key="hibernate.hbm2ddl.auto" value="CREATE" />
            <!-- Multi-tenancy support -->
            <entry key="hibernate.multiTenancy" value="NONE" />
        </map>
    </property>
    <property name="mappingResources">
        <list>
            <TENANT SPECIFIC SCHEMA MAPPING RESOURCES />
        </list>
    </property>
</bean>

Code used to create the schema

public boolean createSchema(final String tenantId) throws SQLException {
    boolean result = false;

    if(_configuration != null && _dataSource != null) {

        // Get a local configuration to configure
        final Configuration tenantConfig = _configuration;

        // Set the properties for this configuration
        Properties props = new Properties();
        props.put(Environment.DEFAULT_SCHEMA, tenantId);
        tenantConfig.addProperties(props);

        // Get connection
        Connection connection = DriverManager.getConnection(_dataSource.getUrl(), 
                _dataSource.getUsername(), _dataSource.getPassword());

        // Create the schema
        connection.createStatement().execute("CREATE SCHEMA " + tenantId + "");

        // Run the schema update from configuration
        SchemaUpdate schemaUpdate = new SchemaUpdate(tenantConfig);
        schemaUpdate.execute(true, true);

        // Set the schema
        connection.createStatement().execute("SET SCHEMA " + tenantId + "");

        // Set the result
        result = true;

    } else if(_configuration == null) {
        if(_LOGGER.isWarnEnabled()) {
            _LOGGER.warn("No configuration was specified for " + getClass().getSimpleName());
        }
    } else if(_dataSource == null) {
        if(_LOGGER.isWarnEnabled()) {
            _LOGGER.warn("No dataSource was specified for " + getClass().getSimpleName());
        }
    }

    return result;
}

Note that the _configuration in this code came from the Non Multi-Tenant LocalSessionFactoryBean