java11-collectors-joining

The main goal of this project is to show Collectors.joining API and String.join.

preface

collectors

public static 
Collector<CharSequence, ?, String> 
joining()

public static 
Collector<CharSequence, ?, String> 
joining(CharSequence delimiter)

public static 
Collector<CharSequence, ?, String> 
joining(CharSequence delimiter,
        CharSequence prefix,
        CharSequence suffix)

string

public static 
String 
join(CharSequence delimiter, CharSequence... elements)

public static 
String 
join(CharSequence delimiter, Iterable<? extends CharSequence> elements)

project description

We provide tests for mentioned above methods.

• "a", "b", "c" -> "abc"

  Stream.of("a", "b", "c").collect(Collectors.joining());
  

  String.join("", "a", "b", "c");
  

• "a", "b", "c" -> "a,b,c"

  Stream.of("a", "b", "c").collect(Collectors.joining(","));
  

  String.join(",", List.of("a", "b", "c"));
  

• "a", "b", "c" -> "prefix-a,b,c-suffix"

  Stream.of("a", "b", "c").collect(Collectors.joining(",", "prefix-", "-suffix"));
  

remarks

• If you don't need to - don't use streams - String.join is faster.
• If you want to customize joining - take a look at StringJoiner - please refer my other github project StringJoiner.
• Collectors.joining and String.join is internally implemented using StringJoiner / StringBuilder.