How to effectively concatenate multiple String variables each from the list of objects?

Peters_ :

I would like to go through a list of objects and concatenate several Strings for each variable:

final StringBuilder xBuilder = new StringBuilder();
final StringBuilder yBuilder = new StringBuilder();
final StringBuilder zBuilder = new StringBuilder();

someObjects.forEach(obj -> {
  A a = obj.getA();
  xBuilder.append(obj.getX() + ",");
  yBuilder.append(obj.getY() + ",");
  zBuilder.append(a.getZ() + ",");
});

Is there any more effective way than creating several StringBuilders for each variable?

Eugene :

Well, you do want 3 separate Strings here, so looks just fine to create 3 StringBuilder(s).. You could alternatively use a StringJoiner though:

StringJoiner xJoiner = new StringJoiner(",");
someObjects.forEach(obj -> {
    xJoiner.join(obj.getX();
});