Bug 153896 Improve the performance of BIRT datetime-converting
The current datetime converting algorithm in birt.core, xml&flatfile ODA implementations are not efficient enough.This is because we use java's SimpleDateTimeFormatter to parse ISO8601 compatible date/time values. We should write our own datatime string parser for ISO8601 datetime format.
core/org.eclipse.birt.core/src/org/eclipse/birt/core/data/DataTypeUtil.java
|| source.matches( ".*[0-9]+:[0-9]+.*" );
		for ( int i = DEFAULT_DATE_STYLE; i <= DateFormat.SHORT; i++ )
		{
			for ( int j = DEFAULT_DATE_STYLE; j <= DateFormat.SHORT; j++ )
			{
				dateFormat = DateFormatHolder.getDateTimeInstance( i, j, locale );
				try
				{
					resultDate = dateFormat.parse( source );
					return resultDate;
				}
				catch ( ParseException e1 )
				{
				}
			}
			 
			if ( !existTime )
			{
				dateFormat = DateFormatHolder.getDateInstance( i, locale );
				try
				{
					resultDate = dateFormat.parse( source );
					return resultDate;
				}
				catch ( ParseException e1 )
				{
				}
			}
		}