What's the best way to build a string of delimited items in Java?

Question

While working in a Java app, I recently needed to assemble a comma-delimited list of values to pass to another web service without knowing how many elements there would be i

Answer 1

Java 8 Native Type

List example;
example.add(1);
example.add(2);
example.add(3);
...
example.stream().collect(Collectors.joining(","));

Java 8 Custom Object:

List person;
...
person.stream().map(Person::getAge).collect(Collectors.joining(","));