Bug 330873 Enable the ODA Runtime framework to run on non-OSGi platform
The ODA framework currently requires an ODA runtime extension to run as an OSGi bundle. This enhancement calls for enabling support to run on non-OSGi platform, if needed, such as in a J2EE application without OSGi.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/odaconsumer/DriverManager.java
private static final String sm_className = DriverManager.class.getName();
	private static LogHelper sm_logger;
	private DriverManager()
	{
	}
	
	/**
	 * Returns a <code>DriverManager</code> instance for loading drivers and 
	 * handling driver-related tasks.
	 * @return	a <code>DriverManager</code> instance.
	 */
	public static DriverManager getInstance()
	{
		if( sm_driverManager == null )
		synchronized( DriverManager.class )
		{
			if ( sm_driverManager == null )
				sm_driverManager = new DriverManager();
		}
		return sm_driverManager;
	}
    
    /**
     * Singleton instance release method.
     */
    static void releaseInstance()
    {
    	sm_driverManager = null;
        sm_logger = null;