Pass multiple args to a method with varargs of Object type

Question

In Java, I am trying to use a method from a library which accepts varargs of Object type:

static Result process(Object head, Object... tail)

In my code, the number of arguments is known at run time, so I tried to use an array to collect all arguments and pass them to process(..) :

T[] items = ...;
Result r = process(items);

However, as Array itself is an Object, the call does not unwrap array items and the whole array is considered as a single argument.

Any idea how multiple arguments can be boxed and passed to a method with varargs of Object type?

Answer 1

You have a non-variadic parameter head .

This means that you require at least head to be passed to the method, with optional variadic arguments after.

Therefore, you should call:

Object[] allArgs = new Object[]{object1, object2, object3};
Object[] varags = Arrays.copyOfRange(allArgs, 1, allArgs.length);
process(allArgs[0], varags)