Question

Suppose our application have only one thread. and we are using StringBuffer then what is the problem?

I mean if StringBuffer can handle multiple threads through synchronization, what is the problem to work with single thread?

Why use StringBuilder instead?

Answer 1

StringBuffers are thread-safe, meaning that they have synchronized methods to control access so that only one thread can access a StringBuffer object’s synchronized code at a time. Thus, StringBuffer objects are generally safe to use in a multi-threaded environment where multiple threads may be trying to access the same StringBuffer object at the same time.

StringBuilder's access is not synchronized so that it is not thread-safe. By not being synchronized, the performance of StringBuilder can be better than StringBuffer. Thus, if you are working in a single-threaded environment, using StringBuilder instead of StringBuffer may result in increased performance. This is also true of other situations such as a StringBuilder local variable (ie, a variable within a method) where only one thread will be accessing a StringBuilder object.

So, prefer StringBuilder because,

• Small performance gain.
• StringBuilder is a 1:1 drop-in replacement for the StringBuffer class.
• StringBuilder is not thread synchronized and therefore performs better on most implementations of Java

Check this out :

• Don’t Use StringBuffer!
• StringBuffer vs. StringBuilder performance comparison