StringJoiner

Java 8 – StringJoiner example

1. StringJoiner

• 1.1 Join String by a delimiter

  StringJoiner sj = new StringJoiner(",");
      sj.add("aaa");
      sj.add("bbb");
      sj.add("ccc");
      String result = sj.toString(); //aaa,bbb,ccc

  COPY

• 1.2 Join String by a delimiter and starting with a supplied prefix and ending with a supplied suffix.

  StringJoiner sj = new StringJoiner("/", "prefix-", "-suffix");
      sj.add("2016");
      sj.add("02");
      sj.add("26");
      String result = sj.toString(); //prefix-2016/02/26-suffix

  COPY

  2. String.join

  StringJoiner is used internally by static String.join().

• 2.1 Join String by a delimiter.

  //2015-10-31
  String result = String.join("-", "2015", "10", "31" );

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• 2.2 Join a List by a delimiter.

  List<String> list = Arrays.asList("java", "python", "nodejs", "ruby");
  	//java, python, nodejs, ruby
  String result = String.join(", ", list);

  COPY

  3. Collectors.joining

Two Stream and Collectors.joining examples.

• 3.1 Join List example.

	List<String> list = Arrays.asList("java", "python", "nodejs", "ruby");

	//java | python | nodejs | ruby
	String result = list.stream().map(x -> x).collect(Collectors.joining(" | "));

• 3.2 Join List