Java – Joining a List with Commas and ‘and’

apache-commonsjava

Given a list

List<String> l = new ArrayList<String>();
l.add("one");
l.add("two");
l.add("three");

I have a method

String join(List<String> messages) {
        if (messages.isEmpty()) return "";
        if (messages.size() == 1) return messages.get(0);
        String message = "";
        message = StringUtils.join(messages.subList(0, messages.size() -2), ", ");
        message = message + (messages.size() > 2 ? ", " : "") + StringUtils.join(messages.subList(messages.size() -2, messages.size()), ", and ");
        return message;
    }

which, for l, produces "one, two, and three".
My question is, is there a standard (apache-commons) method that does the same?, eg

WhatEverUtils.join(l, ", ", ", and ");

To clarify. My problem is not getting this method to work. It works just as I want it to, it's tested and all is well. My problem is that I could not find some apache-commons-like module which implements such functionality. Which surprises me, since I cannot be the first one to need this.

But then maybe everyone else has just done

StringUtils.join(l, ", ").replaceAll(lastCommaRegex, ", and");

Best Answer

In Java 8 you can use String.join() like following:

Collection<String> elements = ....;
String result = String.join(", ", elements);
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