String, StringBuffer, and StringBuilder

Question

Please tell me a real time situation to compare String, StringBuffer, and StringBuilder?

Answer 1

Difference between String and the other two classes is that String is immutable and the other two are mutable classes.

But why we have two classes for same purpose?

Reason is that StringBuffer is Thread safe and StringBuilder is not. StringBuilder is a new class on StringBuffer Api and it was introduced in JDK5 and is always recommended if you are working in a Single threaded environment as it is much Faster

For complete Details you can read http://www.codingeek.com/java/stringbuilder-and-stringbuffer-a-way-to-create-mutable-strings-in-java/