Java 8 - Join Strings Easily

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StringJoiner

StringJoiner class of package java.util.StringJoiner is very helpful for joining delimiter seprated string.

It is used to build a characters sequence separated by a delimiter and optionally starting with a supplied prefix and ending with a supplied suffix.

Example

 If we want to create a string of names seperated by ':' and enclosed in '[' ']' braces than we can write   code as below

 StringJoiner sj = new StringJoiner(":", "[", "]"); ----> 1
 sj.add("George");
 sj.add("Sally");
 sj.add("Fred");
 String requiredString = sj.toString();

 If we print 'requiredString' the output will be as below.

 "[George:Sally:Fred]"

 Note : In line 1 of above example delimiter ':' is compulsory parameter and the prefix '[' and sufix ']'   are optional parameters

Static join() of String

Static method join() from String class is very handy for joining strings in collections

Example

 Set stringSet = new HashSet();
 stringSet.add("Sachin");
 stringSet.add("Rahul");
 stringSet.add("Saurav");
 String newString = String.join(",", stringSet);

 If we print 'newString' the output will be as below.
 "Saurav,Rahul,Sachin"