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
String stringValue = (String) evaValue;
			value = toIntegerValue( evaValue );
			if ( value == null )
			{
				try
				{
					
					value = Double.valueOf( stringValue );
				}
				catch ( NumberFormatException e1 )
				{
					try
					{
						
						value = new BigDecimal( stringValue );
					}
					catch ( NumberFormatException e2 )
					{
						try
						{
							
							value = toDate( stringValue );
						}
						catch ( BirtException e3 )
						{
							value = evaValue;
						}
					}
				}