It’s called varargs.
It allows a method to take any number of arguments. They are accessible as an array in the method:
public void foo(String... args) {
for (String arg : args) {
// do smth with arg.
}
}
This is syntactic sugar. The compiler hides the array creation, so instead of
bar.foo(new String[] {"1", "2", "3"});
you write
bar.foo("1", "2", "3");