Join String list elements with a delimiter in one step [duplicate]

Answer 1

Java 8...

String joined = String.join("+", list);

Documentation: http://docs.oracle.com/javase/8/docs/api/java/lang/String.html#join-java.lang.CharSequence-java.lang.Iterable-

Answer 2

If you just want to log the list of elements, you can use the list toString() method which already concatenates all the list elements.

Answer 3

You can use the StringUtils.join() method of Apache Commons Lang:

String join = StringUtils.join(joinList, "+");

Answer 4

You can use : org.springframework.util.StringUtils;

String stringDelimitedByComma = StringUtils.collectionToCommaDelimitedString(myList);

Answer 5

Or Joiner from Google Guava.

Joiner joiner = Joiner.on("+");
String join = joiner.join(joinList);

Answer 6

If you are using Spring you can use StringUtils.join() method which also allows you to specify prefix and suffix.

String s = StringUtils.collectionToDelimitedString(fieldRoles.keySet(),
                "\n", "<value>", "</value>");