Bug 211004 Failed to remove temp db directory after running multiple reports
Description: I use Report Engine API to do runAndrender, run and dataextract tasks on multiple reports. Before the Platform started, I change the temp folder(System.setProperty( "java.io.tmpdir", TEMP_HOME )). Each task is closed after it finished and I shutdown the Platform after all the tasks finished. In log I found "Fail to remove one or more file in temp db directory,but it will be removed when the VM exits: D:\BIRT_NG\temp/BIRTSampleDB_1196129572031_10a6ae2". In temp folder the BIRTSampleDB_XXX is still here but not removed. I think it is the issue when remove the Temp sampleDB. Build number: 2.3.0.v20071127-0630
data/org.eclipse.birt.report.data.oda.jdbc/src/org/eclipse/birt/report/data/oda/jdbc/JDBCDriverManager.java
throw new NullPointerException( this.resourceHandle.getMessage( ResourceConstants.MISSEDURLANDJNDI ) );
	}
    /**
	 * 
	 * @param url
	 * @return
	 */
	private boolean isBlank(String url) {
		return url == null || url.trim().toString().length() == 0;
	}
    
	/** 
	 * Searches extension registry for connection factory defined for driverClass. Returns an 
	 * instance of the factory if there is a connection factory for the driver class. Returns null
	 * otherwise.
	 */
	private IConnectionFactory getDriverConnectionFactory( String driverClass ) throws OdaException
	{
		loadDriverExtensions();
		
		IConnectionFactory factory = null;
		Object driverInfo = null;
		if ( driverClass != null )
			driverInfo = driverExtensions.get( driverClass);
		
		if ( driverInfo != null )
		{
			
			if ( driverInfo instanceof IConfigurationElement )
			{