public class MyMyBatisModule extends PrivateModule {

    private final String     datasourceLabel;
    private final Properies  datasourceProperties;
    private       List< Key<?> > exposedKeys = new ArrayList< Key<?> >();

    public MyMyBatisModule( String datasourceLabel, Properties datasourceProperties ) {

        this.datasourceLabel = datasourceLabel;
        this.datasourceProperties = datasourceProperties;
    }

    @Override
    protected void configure() {

        install( new InternalMyMyBatisModule( ) );

        for( Key<?> key: keys ) {
            expose( key );
        }
    }

    private class InternalMyMyBatisModule extends MyBatisModule {

        @Override
        protected void initialize( ) {

            environmentId( datasourceLabel );
            Names.bindProperties( binder(), properties );

            install( JdbcHelper.MySQL ); // See JDBC Helper commentary below

            bindDataSourceProviderType( C3p0DataSourceProvider.class ); // Choose whichever one you want
            bindTransactionFactoryType( JdbcTransactionFactory.class );

            // Register your mapper classes here.  These mapper classes will have their
            // keys exposed from the PrivateModule
            //
            // i.e.
            //
            // keys.add( registerMapper( FredMapper.class );
            // kets.add( registerMapper( GingerMapper.class );
        }

        private <T> Key<T> registerMapper( Class<T> mapperClass ) {
            Key<T> key = Key.get( mapperClass, Names.named( datasourceLabel ) );
            bind( key ).to( mapperClass );
            addMapperClass( mapperClass );
            return key;
        }
    }
}

MySQL("jdbc:mysql://${JDBC.host|localhost}:${JDBC.port|3306}/${JDBC.schema}", "com.mysql.jdbc.Driver"),

public class MyBatisModules extends AbstractModule {

    private Map< String, Properties > connectionsProperties;

    public MyBatisModules( Map< String, Properties > = new HashMap< String, Properties > connectionsProperties ) {
        this.connectionsProperties = connectionsProperties; // consider deep copy if appropriate
    }

    @Override
    protected void configure( ) {

        for( Entry< String, Properties > datasourceConnectionProperties : this.connectionsProperties.entrySet() ) {
            install( new MyMyBatisModule( datasourceConnectionProperties.getKey(), datasourceConnectionProperties.getValue() ) );
        }

        bind( MapperRetriever.class ); // See MapperRetriever later

        // bind your DAO classes here.  By wrapping MyBatis Mapper use in DAO implementations, theoretically we
        // can fairly easily change from MyBatis to any other database library just by changing the DAO implementation.
        // The rest of our codebase would remain the same.
        //
        // i.e.
        //
        // bind( FredDao.class ).to( FredDaoMyBatis.class );
        // bind( GingerDao.class).to( GingerDaoMyBatis.class );
    }
}

public class MapperRetriever {

    private final Injector injector;

    @Inject
    public MapperRetriver( Injector injector ) {
        this.injector = injector;
    }

    // The follwing two methods use the example Mappers referenced in the MyMyBatisModule implementation above

    public FredMapper getFredMapper( String datasourceLabel ) {
        return this.injector.getInstance( Key.get( FredMapper.class, Names.named( datasourceLabel ) ) );
    }

    public GingerMapper getGingerMapper( String datasourceLabel ) {
        return this.injector.getInstance( Key.get( GingerMapper.class, Names.named( datasourceLabel ) ) );
    }
}

public interface FredDao {
    Fred selectFred( String datasourceLable, String fredId );
}

public class FredDaoMyBatis implements FredDao {

    private MapperRetriever mapperRetriever;

    @Inject
    public FredDaoMyBatis( MapperRetriever mapperRetriever ) {
        this.mapperRetriever = mapperRetriever;
    }

    @Override
    public Fred selectFred( String datasourceLabel, String fredId ) {
        FredMapper fredMapper = this.mapperRetriever.getFredMapper( datasourceLabel );
        return fredMapper.getFred( fredId );
    }
}

public class DelegatingSqlSessionFactory implements SqlSessionFactory {
    private final Map<String, SqlSessionFactory> factories = new HashMap<>();

    public DelegatingSqlSessionFactory(Map<String, DataSource> dataSources) throws ClassNotFoundException {
        dataSources.forEach((key, ds) -> {
            factories.put(key, createSqlSessionFactory(ds));
        });
    }

    private SqlSessionFactory delegate() {
        // Read from a ThreadLocal to determine correct SqlSessionFactory key
        String key = findKey();
        return factories.get(key);
    }

    @Override
    public SqlSession openSession() {
        return delegate().openSession();
    }

    @Override
    public SqlSession openSession(boolean autoCommit) {
        return delegate().openSession(autoCommit);
    }

    @Override
    public SqlSession openSession(Connection connection) {
        return delegate().openSession(connection);
    }

    @Override
    public SqlSession openSession(TransactionIsolationLevel level) {
        return delegate().openSession(level);
    }

    @Override
    public SqlSession openSession(ExecutorType execType) {
        return delegate().openSession(execType);
    }

    @Override
    public SqlSession openSession(ExecutorType execType, boolean autoCommit) {
        return delegate().openSession(execType, autoCommit);
    }

    @Override
    public SqlSession openSession(ExecutorType execType, TransactionIsolationLevel level) {
        return delegate().openSession(execType, level);
    }

    @Override
    public SqlSession openSession(ExecutorType execType, Connection connection) {
        return delegate().openSession(execType, connection);
    }

    @Override
    public Configuration getConfiguration() {
        return delegate().getConfiguration();
    }
}