Passing a List in as varargs [duplicate]

问题

This question already has answers here:

How to pass an ArrayList to a varargs method parameter? (4 answers)

Closed 4 years ago.

I have a List<Thing> and I would like to pass it to a method declared doIt(final Thing... things). Is there a way to do that?

The code looks something like this:

public doIt(final Thing... things)
{
    // things get done here
}

List<Thing> things = /* initialized with all my things */;

doIt(things);

That code obviously doesn't work because doIt() takes Thing not List<Thing>.

Is there a way to pass in a List as the varargs?

This is in an Android App, but I don't see why the solution will not apply to anything Java

回答1:

Just pass things.toArray(new Thing[things.size()]).

回答2:

The variadic argument is internally interpreted as an array. So you should convert it into an array beforehands. Also in your doIt method you should access things-s elements with array indexing.

来源：https://stackoverflow.com/questions/12220324/passing-a-list-in-as-varargs