No data source found with name (after asking 0 providers)

Hello.

I made everything needed that is described in this article: Adobe Experience Manager Help | Querying MySQL data using an Adobe Experience Manager 6.4 DataSourcePool

I can successfuly get data source instance only after component activation. If I do it during the activation I get this error message: "No data source found with name 'MyDatabase' (after asking 0 providers)".

Here below is the source code. I have no errors getting dataSource if I only call getConnection() method. Activation method is problematic.

I use Adobe Experience Manager (6.2.0.SP1-CFP16) version.

Could I get some assistance? Thanks in advance.

================== THE SOURCE CODE ==================

DataBaseComponent.java:

package test.components;

import java.sql.Connection;

public interface DataBaseComponent {

       Connection getConnection();
}

DataBaseComponentImpl.java:

package test.components.impl;

import org.osgi.service.component.annotations.*;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.sql.DataSource;
import java.sql.Connection;

import com.day.commons.datasource.poolservice.DataSourcePool;
import com.day.commons.datasource.poolservice.DataSourceNotFoundException;

import test.components.DataBaseComponent;

@Component (

   immediate = true,
   scope = ServiceScope.SINGLETON
)

public class DataBaseComponentImpl implements DataBaseComponent {

        private static final String DATA_SOURCE_NAME = "MyDatabase";

        @Reference
        private DataSourcePool dataSourcePool;
        private DataSource dataSource;

        private Logger logger = LoggerFactory.getLogger(getClass());

        public Connection getConnection() {

              Connection con = null;
              if (dataSource != null) {

                  try {

                       con = dataSource.getConnection();
                       return con;
                   } catch (Exception e) {

                       logger.error(e.getMessage());
                  }

             } else {

                  try {

                       dataSource = (DataSource) dataSourcePool.getDataSource(DATA_SOURCE_NAME);
                       con = dataSource.getConnection();
                       logger.info("dataSource in instantiated ...");
                  } catch (Exception e) {

                       logger.error(e.getMessage());
                  }

                  return con;
             }

             return null;
        }

        @Activate
        public void activate() {

              try {

                       dataSource = (DataSource) dataSourcePool.getDataSource(DATA_SOURCE_NAME);
                       logger.info("activation step: dataSource in instantiated ...");
             } catch(DataSourceNotFoundException e) {

                       logger.error(e.getMessage());
              }

       }

}