Question

I am using spring mvc+hibernate+two databases

So for example:
I create 2 sessionFactories. sessionFactory1 (using datasource1) and sessionFactory2 (using datasource2).

Would it be possible to change sessionFactory1 or sessionFactory2 to sessionFactory at runtime so that the dao/s references them. sessionFactory is already autowired to all dao/s.

I am searching for it right now I think @Configuration can help me but I am not sure.

I am trying AbstractRoutingDataSource but don’t think it helps.

Answer 1

AbstractRoutingDataSource will work for you.

First you’ll need to create a class that will store the current DB in use:

public class MyContextHolder {

    private static final ThreadLocal<String> contextHolder = new ThreadLocal<String>();

    public static void setDBContext(String dBContext) {
        contextHolder.set(dBContext);
    }

    public static String getDBContext() {
        return (String) contextHolder.get();
    }

    public static void clearDBContext() {
        contextHolder.remove();
    }

}

You’ll need to create a class that extends this one and implements determineCurrentLookupKey(), and return the current db you have in your context holder:

import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;

public class MyRoutingDataSource extends AbstractRoutingDataSource {

    @Override
    protected Object determineCurrentLookupKey() {
        return MyContextHolder.getDBContext();
    }
}

See the example in http://blog.springsource.org/2007/01/23/dynamic-datasource-routing/.
It worked fine for me.