CommonJdbcDriverProvider.java

package org.springframework.roo.addon.jdbc.polling.internal;

import java.sql.Driver;
import java.sql.DriverManager;

import org.apache.felix.scr.annotations.Component;
import org.apache.felix.scr.annotations.Service;
import org.osgi.framework.BundleContext;
import org.osgi.service.component.ComponentContext;
import org.springframework.roo.addon.jdbc.polling.JdbcDriverProvider;
import org.springframework.roo.support.osgi.BundleFindingUtils;

/**
 * Basic implementation of {@link JdbcDriverProvider} that provides common JDBC
 * drivers. To be returned by this provider, it is necessary the JDBC driver has
 * been declared as an optional import within the JDBC add-on's OSGi bundle
 * manifest.
 * 
 * @author Alan Stewart
 * @author Ben Alex
 * @since 1.1
 */
@Component
@Service
public class CommonJdbcDriverProvider implements JdbcDriverProvider {

  private BundleContext bundleContext;

  protected void activate(final ComponentContext context) {
    bundleContext = context.getBundleContext();
  }

  protected void deactivate(final ComponentContext context) {
    bundleContext = null;
  }

  public Driver loadDriver(final String driverClassName) throws RuntimeException {
    // Try a search
    final Class<?> clazz =
        BundleFindingUtils.findFirstBundleWithType(bundleContext, driverClassName);

    if (clazz == null) {
      // Let's give up given it doesn't seem to be loadable
      return null;
    }

    if (!Driver.class.isAssignableFrom(clazz)) {
      // That's weird, it doesn't seem to be a driver
      return null;
    }

    // Time to create it and register etc
    try {
      final Driver result = (Driver) clazz.newInstance();
      DriverManager.registerDriver(result);
      return result;
    } catch (final Exception e) {
      throw new IllegalStateException("Unable to load JDBC driver '" + driverClassName + "'", e);
    }
  }
}