StringBuffer and StringBuilder

Sometimes it is necessary to build a string from a shorter string. For example, keys or words from a file. A string connection is used to achieve this goal in a less efficient way. Each time a string is concatenated, a new string object is constructed, which is time consuming and wasteful. You can avoid this problem by using the StringBuilder class.

If you need to build a string with a lot of small strings, we can do it in one way:

New StringBuilder ();   = Sb.tostring ();

The StringBuilder class was introduced in JDK 5.0, and the predecessor of this class is StringBuffer, which is slightly less efficient, but allows the operation of adding or removing characters in a multithreaded manner. But the API for two classes is the same.

StringBuffer and StringBuilder