to speed up String concating i am using StringBuffer, but it is synchronized what do i do; should i go back to '+' operator for String concating or should i use StringBuffer as suggested on this page http://www.protomatter.com/nate/java-optimization/ by using one synchronized block for multiple append()
I think if you time a StringBuffer versus a StringBuilder you will see very little difference -- uncontested synchronization is cheap. So in 1.4, use a StringBuffer when appropriate and don't sweat the synch.
Jeff's right. In a web application, your bottlenecks are probably going to be network and database related. Unless you can profile your system and identify string concatenation as a problem, don't worry about it.