stringbuffer vs stringbuilder

StringBuilder was introduced in JDK 1.5. What's the difference between StringBuilder and StringBuffer? According to javadoc, StringBuilder is designed as a replacement for StringBuffer in single-threaded usage. Their key differences in simple term:

• StringBuffer is designed to be thread-safe and all public methods in StringBuffer are synchronized. StringBuilder does not handle thread-safety issue and none of its methods is synchronized.


• StringBuilder has better performance than StringBuffer under most circumstances.


• Use the new StringBuilder wherever possible.