How to set custom connection properties on DataSource in Spring Boot 1.3.x with default Tomcat connection pool

Question

I need to set some specific Oracle JDBC connection properties in order to speed up batch INSERTs (defaultBatchValue) and mass SELECTs

Answer 1

After digging around in the Tomcat code for a bit, I found that the dataSource.getPoolProperties().getDbProperties() is the Properties object that will actually get used to generate connections for the pool.

If you use the BeanPostProcessor approach mentioned by @m-deinum, but instead use it to populate the dbProperties like so, you should be able to add the properties in a way that makes them stick and get passed to the Oracle driver.

import java.util.Properties;
import org.apache.tomcat.jdbc.pool.DataSource;
import org.apache.tomcat.jdbc.pool.PoolConfiguration;

@Component
public class OracleConfigurer implements BeanPostProcessor {
    @Override
    public Object postProcessBeforeInitialization(Object bean, String name) throws BeansException {
        if (bean instanceof DataSource) {
            DataSource dataSource = (DataSource)bean;
            PoolConfiguration configuration = dataSource.getPoolProperties();
            Properties properties = configuration.getDbProperties();
            if (null == properties) properties = new Properties();
            properties.put("defaultRowPrefetch", 1000);
            properties.put("defaultBatchValue", 1000);
            configuration.setDbProperties(properties);
        }
        return bean;
    }

    @Override
    public Object postProcessAfterInitialization(Object bean, String name) throws BeansException {
        return bean;
    }
}