Difference between StringBuilder and StringBuffer

Question

What is the main difference between StringBuffer and StringBuilder? Is there any performance issues when deciding on any one of these?

Answer 1

Pretty Good Question

Here are the differences, i have noticed :

StringBuffer :-

StringBuffer is  synchronized
StringBuffer is  thread-safe
StringBuffer is  slow (try to write a sample program and execute it, it will take more time than StringBuilder)

StringBuilder:-

 StringBuilder is not synchronized 
 StringBuilder is not thread-safe
 StringBuilder performance is better than StringBuffer.

Common thing :-

Both have same methods with same signatures. Both are mutable.