What is the difference between String , StringBuilder and StringBuffer ? code example

Example 1: stringbuffer vs stringbuilder vs string in java

The StringBuffer and StringBuilder class both produces mutable string objects.
 The main difference between them is that StringBuffer is thread safe;
 StringBuilder is not thread safe.
String is immutable and thread safe.
We are using StringBuffer when we are doing parallel
testing since it is a thread safe.

Example 2: stringbuilder vs stringbuffer

They both mutable, they are exactly same but
String buffer is thread safe so it runs slower
than String builder.
We are using StringBuffer when we are doing parallel
testing since it is a thread safe.